JPH0646901A - Composition for ski boots - Google Patents

Abstract

PURPOSE:To provide a composition for ski boots excellent in physical property, surface gloss and antistatic property by compounding polyamide, modified polyolefin and modified olefin elstmer in a specified range. CONSTITUTION:In less than 50wt.% of polyamide resin, mechanical strength and damage preventing property are degraded, and when the polyamide resin exceeds 90wt.%, the retention of mechanical strength in absorbing water is lowered. Also when the modified polyolefin or polyolefin resin composition containing more than 1wt.% of modified polyolefin occupies less than 2wt.%, the retention of mechanical strength in absorbing water is lowered. On the other hand, when the polyolefin resin compound exceeds 40wt.%, the damage preventing property is lowered while the resin compound is liable to be electrified. Further, when the modified polyolefin elastmer or olefin elastmer compound containing more than 1wt.% of modified orefin elastmer is less than 2wt.%, the impact resistance, particularly at a low temperature is insufficient, while in more than 40wt.% of the elastmer comound, the mechanical strength and surface gloss are degraded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for ski boots, which is particularly excellent in mechanical strength, impact resistance at low temperature, scratch resistance and stress cracking resistance, and has a good surface gloss. The present invention relates to a composition for ski boots that is difficult to be charged.

[0002]

2. Description of the Related Art In recent years,
Various thermoplastic resins have been used in various sports goods. For example, ski boots are required to have fashionable properties such as glossy coloring, as well as mechanical strength and weight reduction.

As a resin for such a ski boot, a polyamide resin is widely used because of its excellent mechanical strength. However, the polyamide resin, when used alone, lacks flexibility, particularly at low temperatures, is easily broken by impact during use, and has high water absorption, so that it gets wet when snowing, etc. In this case, there is a problem that the mechanical strength is significantly reduced.

It is also conceivable to use polyolefin such as high density polyethylene instead of polyamide.
However, since high-density polyethylene has almost no water absorbency, it has a high electrostatic property, so that it easily adsorbs dust or the like during display, and therefore has a problem that its appearance is likely to deteriorate. In addition, when a solvent containing a surfactant is used to remove dust that has adhered, there is a problem that cracks occur due to poor stress cracking resistance.

For the purpose of solving the above-mentioned problems, a rubber component is blended with a polyamide resin or a polyolefin, but a rubber component blended with a polyamide resin has a rigidity in practical use. Is low,
When ski boots are used, there is a problem that the sliding performance is reduced. In addition, there is a problem that a blend of polyolefin with a rubber-based component has no surface gloss and is not suitable for recent ski boots that require gorgeousness.

Further, Japanese Patent Publication No. 2-24121 discloses a ski shoe having an upper skin and / or a bottom formed by molding a thermoplastic resin, wherein the resin is a polyamide resin (A),
An acid-modified olefin copolymer (B) and a plasticizer (C),
(A) / (B) = 40/60 to 90/10, (C) / {(A) +
(B)} = 1/100 to 20/100 is disclosed, which is an elastic ski shoe that is a polyamide resin composition.

However, although the ski shoes made of the above composition show some improvement in impact resistance at low temperature, they do not yet have sufficient impact resistance.
Moreover, since it is inferior in scratch resistance, there is a problem in that it is easily scratched during assembly of the molded product and during transportation. Such susceptibility to scratches is an important problem in ski boots in which fashionability is regarded as important in recent years.

Further, it has been attempted to add flexibility to a resin component to improve flexibility and to improve impact resistance and stress cracking resistance. Then, the plasticizer bleeds on the surface of the molded article. Since it comes out, there is a problem that the appearance is impaired.

Therefore, an object of the present invention is to provide a composition for ski boots which is excellent in mechanical strength, impact resistance at low temperature, scratch resistance and stress cracking resistance, has a good surface gloss and is hard to be charged. Is to provide.

[0010]

As a result of earnest research in view of the above object, the present inventors have identified a polyamide resin, a modified polyolefin by a monomer having a carboxyl group or an epoxy group, and a modified olefin elastomer. The composition containing within the range is excellent in mechanical strength, impact resistance at low temperature, scratch resistance and stress cracking resistance, has a good surface gloss, and is found not to be easily charged. Invented the invention.

That is, the composition for ski boots of the present invention comprises (a) a polyamide resin of 50 to 90% by weight and (b) a modified polyolefin, or a polyolefin resin composition of 2 to 40 containing 1% by weight or more of the modified polyolefin. weight%
And (c) a modified olefin-based elastomer, or 2 to 40% by weight of an olefin-based elastomer composition containing 1% by weight or more of the modified olefin-based elastomer.

The present invention will be described in detail below. First, each component constituting the ski boot composition of the present invention will be described.

(A) Polyamide Resin In the present invention, (a) the polyamide resin includes hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4- or 2,4,4, -trimethylhexamethylenediamine, Aliphatic, alicyclic or aromatic diamines such as 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xylylenediamine, and adipine A polyamide produced from an aliphatic, alicyclic or aromatic dicarboxylic acid such as an acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, 6
From polyamides prepared from aminocarboxylic acids such as aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, polyamides prepared from lactams such as ε-caprolactam, ω-dodecalactam, and components thereof And a mixture of these polyamides. Specific examples include nylon 6, nylon 66, nylon 610, nylon 9, nylon 6/66, nylon 66/610, nylon 6/11, nylon 6/12, nylon 12, nylon 46, and amorphous nylon. . Of these, nylon 6 and nylon 66 are preferable in terms of good rigidity and heat resistance.

The molecular weight of the above polyamide resin is not particularly limited, but those having a relative viscosity η _r (measured in JIS K6810, 98% sulfuric acid) of 0.5 or more are usually used, and among them, those having a mechanical viscosity of 2.0 or more have a mechanical strength. It is preferable because it is excellent.

(B) Modified Polyolefin (b) The modified polyolefin is a modified polyolefin with a monomer having a carboxyl group or an epoxy group.

In the modified polyolefin, the polyolefin to be modified is ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, etc. Examples thereof include a copolymer with propylene or another α-olefin, or a copolymer of two or more kinds of these α-olefins. Among these, polyethylene such as low density polyethylene, linear low density polyethylene, medium density polyethylene and high density polyethylene and polypropylene are preferable. Polypropylene is not limited to a homopolymer, and a random or block copolymer with another α-olefin containing a propylene component in an amount of 50 mol% or more, preferably 80 mol% or more can also be used. As the comonomer copolymerized with propylene, there are ethylene and other α-olefins, and ethylene is particularly preferable.

Melt index of the above polyethylene
(MI, 190 ° C., 2.16 kg load) is preferably 0.1 to 100 g / 10 min, and particularly preferably 5 to 20 g / 10 min.

The melt flow rate of polypropylene (MFR, 230 ° C., 2.16 kg load) is 0.1 to 100 g / 10
Min is preferable, and 0.5 to 10 g / 10 min is particularly preferable.

Examples of such a polyolefin-modifying monomer include monomers containing a carboxyl group or an epoxy group.

The carboxylic group-containing monomer is preferably an unsaturated carboxylic acid or an anhydride thereof, for example, a monocarboxylic acid such as acrylic acid or methacrylic acid, maleic acid,
Dicarboxylic acids such as fumaric acid and itaconic acid, maleic anhydride, itaconic anhydride, endo-bicyclo- [2,2,1] -5
Examples thereof include dicarboxylic acid anhydrides such as -heptene-2,3-dicarboxylic acid anhydride (hymic anhydride), and dicarboxylic acid and its anhydride are particularly preferable.

Further, as the epoxy group-containing monomer,
For example, methacrylic acid glycidyl ester, acrylic acid glycidyl ester and the like can be mentioned.

Further, the following general formula (1):

[Chemical 1] (In the formula, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n represents an integer of 1 to 4. A glycidyl compound having an acrylamide group and an epoxy group represented by the formula (4) can also be used as the modifying monomer.

Preferred glycidyl compounds include those represented by the following general formula (2).

[Chemical 2] (In the formula, R is H or an alkyl group having 1 to 6 carbon atoms.)

Such a glycidyl compound can be produced, for example, by the method disclosed in JP-A-60-130580.

The modified polyolefin with the modifying monomer may be a block copolymer, a graft copolymer, a random copolymer or an alternating copolymer.

The content of the modifying monomer in the modified polyolefin is preferably in the range of 0.01 to 5% by weight, preferably 0.02 to 3% by weight. If the amount of modification by the modifying monomer is less than 0.01% by weight, the effect of improving the compatibility between the polyolefin and the polyamide resin will not be sufficient, and if it exceeds 5% by weight, the mechanical strength will decrease.

The modified polyolefin can be produced by either a solution method or a melt-kneading method. In the case of the melt-kneading method, the polyolefin, the modifying monomer and the catalyst are put into an extruder, a biaxial kneader or the like, and heated to a temperature of 180 to 250 ° C. to be kneaded while melting. In the case of the solution method, the above-mentioned starting materials are dissolved in an organic solvent such as xylene and the stirring is carried out at a temperature of 90 to 140 ° C. In any case, a usual radical polymerization catalyst can be used as a catalyst, for example, benzoyl peroxide, lauroyl peroxide, ditert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, Peroxybenzoic acid, peroxyacetic acid, tertiary butyl peroxypivalate, peroxides such as 2,5-dimethyl-2,5-ditertiary butyl peroxyhexyne and diazo compounds such as azobisisobutyronitrile Etc. are preferred. The amount of the catalyst added is about 1 to 100 parts by weight based on 100 parts by weight of the modifying monomer.

Regarding the melt viscosity of the modified polyolefin as described above, in the case of modified polypropylene, the melt flow rate (MFR, 190 ° C., 1050 g load) is preferably 0.1 to 500 g / 10 minutes, and in the case of modified polyethylene. , Melt index (MI, 190 ℃, 1050 g load) 0.1 to 50 g
/ 10 minutes is preferred.

In the present invention, a polyolefin resin composition obtained by diluting the above-mentioned modified polyolefin with an unmodified polyolefin can also be used. As the unmodified polyolefin, the above-mentioned polyolefin to be modified can be used.

In the case of the polyolefin resin composition, the proportion of the modified polyolefin is 1% by weight or more, preferably 5% by weight or more, based on 100% by weight of the modified polyolefin and the unmodified polyolefin. When the content of the modified polyolefin is less than 1% by weight, there is no sufficient effect for improving the compatibility between the polyolefin resin composition (modified polyolefin + unmodified polyolefin) and the polyamide resin.

However, the modified polyolefin + unmodified polyolefin is 100% by weight, and the content of the modifying monomer is preferably 0.005% by weight or more, particularly 0.01 to 1% by weight. When the content of the modifying monomer is less than 0.005% by weight, there is no sufficient effect for improving the compatibility between the polyolefin resin and the polyamide resin.

(C) Modified Olefin-Based Elastomer (c) The modified olefin-based elastomer is a olefin-based elastomer modified with a monomer having a carboxyl group or an epoxy group.

In the above modified olefin elastomer, the olefin elastomer to be modified is ethylene, propylene, butene-1, hexene-1,4-
Examples thereof include copolymer rubbers of two or more kinds of α-olefins such as methylpentene-1, and copolymer rubbers of α-olefins and other kinds of monomers. As the above-mentioned two or more copolymer rubbers of α-olefin, typically, ethylene-propylene copolymer rubber (EPR), ethylene-butene copolymer rubber (EBR), and ethylene-propylene- Diene copolymer rubber (EPDM) may be mentioned. As the diene in the ethylene-propylene-diene copolymer rubber (EPDM), a non-conjugated diene such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene or a conjugated diene such as butadiene or isoprene is used. be able to. Further, vinyl acetate, acrylic acid ester and the like can be used as the other monomer copolymerized with the α-olefin. A typical example of a copolymer of α-olefin and another monomer is ethylene-
Examples thereof include vinyl acetate copolymer (EVA).

Ethylene-Propylene Copolymer Rubber (EPR)
Preferably has an ethylene content of 40 to 90 mol% and a propylene content of 10 to 60 mol%. A more preferable range is 50 to 90 mol% of ethylene and 10 to 10 of propylene.
It is 50 mol%.

The melt index of EPR (190
C., 2.16 kg load) is preferably in the range of 0.5 to 15 g / 10 minutes, more preferably 3 to 9 g / 10 minutes.

The ethylene-butene copolymer rubber (EBR) is
The ethylene content is preferably 60 to 97 mol%, and the butene-1 content is preferably 3 to 40 mol%. A more preferred range is 80 to 95 mol% for ethylene and 5 to 20 mol% for butene-1.

The EBR melt index (190
C., 2.16 kg load) is preferably in the range of 0.5 to 15 g / 10 minutes, more preferably 3 to 9 g / 10 minutes.

The ethylene-propylene-diene copolymer (EPDM) has an ethylene content of 40 to 89 mol%, a propylene content of 10 to 59 mol%, and a diene content of 1 to 10 mol%. % Is preferable.

Furthermore, the Mooney viscosity of EPDM ML _{1 + 8} (100
C.) is preferably in the range of 5 to 100, more preferably 10 to 50.

The ethylene-propylene-diene copolymer rubber (EPDM) and the ethylene-propylene copolymer rubber (EPR) basically consist of the above repeating units. Within the range that does not impair the characteristics, for example, butene-1 or 4-methylpentene-1
Other repeating units, such as repeating units derived from α-olefins such as, may be included up to a proportion of 10 mol% or less.

Further, in the present invention, a hydrogenated styrene-butadiene block copolymer (SEBS: styrene-ethylene / butylene-polymer) is used as the olefin elastomer.
Styrene block copolymer), hydrogenated styrene-isoprene block copolymer (SEPS: styrene-ethylene
An elastomer such as propylene-styrene block copolymer) can also be used.

The content of styrene in the elastomer component is preferably 5 to 50% by weight, and the melt flow rate (MFR, 230 ° C., 2.16 kg) is 0.1.
It is preferably in the range of -100 g / 10 min, more preferably 1-50 g / 10 min.

As the monomer for modifying such an olefinic elastomer, the same one as the modified polyolefin described above can be used.

The content of the modifying monomer in the modified olefin elastomer is 0.01-5% by weight, preferably 0.5-.
It is preferable that the content is within the range of 3% by weight. If the amount of modification by the modifying monomer is less than 0.01% by weight, the effect of improving the compatibility between the olefin-based elastomer and the polyamide resin is not sufficient, and if it exceeds 5% by weight, the mechanical strength decreases.

The modified olefin elastomer can be produced by either the solution method or the melt-kneading method as in the case of the modified polyolefin described above. In the case of the melt kneading method, the olefin elastomer, the modifying monomer and the catalyst are put into an extruder, a twin-screw kneader or the like, and heated to a temperature of 150 to 250 ° C. to be kneaded while melting. In the case of the solution method, the above starting materials are dissolved in an organic solvent such as xylene,
Stir at a temperature of ~ 140 ° C.

In the present invention, an olefinic elastomer composition obtained by diluting the above-mentioned modified olefinic elastomer with an unmodified olefinic elastomer can also be used. As the unmodified olefin-based elastomer, the above-described modification-target olefin-based elastomer can be used.

In the case of an olefin elastomer composition,
The ratio of the modified olefin elastomer is 1% by weight or more, preferably 10% by weight, based on 100% by weight of the modified olefin elastomer and the unmodified olefin elastomer.
That is all. When the content of the modified olefin-based elastomer is less than 1% by weight, there is no sufficient effect for improving the compatibility between the olefin-based elastomer and the polyamide resin.

However, modified olefin elastomer +
Unmodified olefinic elastomer is 100% by weight, and the content of modifying monomer is 0.005% by weight or more, especially
It is preferably 0.1 to 2% by weight. When the content of the modifying monomer is less than 0.001% by weight, the effect of improving the compatibility between the olefin elastomer and the polyamide resin is not sufficient.

The mixing ratio of each component as described above is (a)
The polyamide resin is 50 to 90% by weight, preferably 55 to 85% by weight, and (b) the modified polyolefin (or the polyolefin resin composition containing the same) is 2 to 40% by weight, preferably 5 to 30% by weight. And (c) the modified olefin elastomer (or the olefin elastomer composition containing the same) is 2 to 40% by weight, preferably 5 to 30% by weight.

If the polyamide resin content is less than 50% by weight, the mechanical strength and hardness (scratch resistance) will decrease, while if it exceeds 90% by weight, the retention rate of mechanical strength during water absorption will decrease.

When the content of the modified polyolefin (or the polyolefin resin composition containing the same) is less than 2% by weight,
The retention rate of mechanical strength during water absorption is lowered, while when it exceeds 40% by weight, hardness is lowered and charging is likely to occur.

The modified olefin elastomer (or the olefin elastomer composition containing the same) is 2
If it is less than 40% by weight, impact resistance, particularly impact resistance at low temperature, is not sufficient, while if it exceeds 40% by weight, mechanical strength and surface gloss are deteriorated.

For the purpose of modifying the composition for ski boots of the present invention, other additives such as an inorganic filler, a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant, and a plasticizer are also included. , An antistatic agent, a release agent, a nucleating agent and the like can be added.

The ski boot composition of the present invention comprising the above-mentioned components is kneaded in a molten state at 220 to 300 ° C. using an extruder such as a single screw extruder or a twin screw extruder. Can be obtained by

[0055]

The composition for ski boots of the present invention comprises a polyamide resin, a modified polyolefin and a modified olefin-based elastomer within respective specific ranges, so that mechanical strength, impact resistance at low temperature, It has excellent scratch resistance and stress cracking resistance, good surface gloss, and is difficult to be charged.

Although the reason why such an effect is obtained is not always clear, the mechanical properties of the polyamide resin can be improved by blending the polyamide resin, the modified polyolefin and the modified olefin elastomer within the scope of the present invention. Strength, scratch resistance (hardness), stress cracking resistance and antistatic property, low water absorption of the modified polyolefin, and impact resistance of the modified olefin elastomer are suitably exhibited for ski boots, respectively. Is considered to be.

[0057]

The present invention will be described in more detail by the following examples. The following resin components were used as raw materials. [1] Polyamide resin Nylon 6: Ny6 [DL-INT, manufactured by JSR-Allied Co., Ltd., relative viscosity (JIS K6810, measured in 98% sulfuric acid) [η _r ] 2.7] [2] Modified polyolefin / anhydrous Maleic acid-modified polypropylene CMPP: [Maleic anhydride addition amount 0.03% by weight, melt flow rate (190 ° C, 1050 g load) 5 g / 10 minutes] [3] Modified olefin elastomer / maleic anhydride-modified ethylene-butene copolymer rubber CMEBR [Addition amount of maleic anhydride 0.9% by weight, melt flow rate (190 ° C, 1050 g load) 2 g / 10 minutes] [4] Polyolefin / propylene-ethylene block copolymer BPP: [Ethylene content 13% by weight, melt Flow rate (230 ℃, 2160g load) 3g / 10 minutes] ・ High density polyethylene HDPE: [Melt index (190 ℃, 2160g load)
3 g / 10 min, density 0.950 g / cm ³ ]

Examples 1 to 4 and Comparative Examples 1 to 4 Polyamide resin (Ny6), polypropylene (BPP), modified polypropylene (CMP) at the compounding ratios shown in Table 1 .
P), modified olefin elastomer (CMEBR) and high-density polyethylene (HDPE) were dry blended and kneaded with a 45 mmφ twin-screw extruder (L / D = 30) at 250 ° C. to obtain pellets of the composition. .

Using the obtained pellets, a test piece for a physical property test to be described later was prepared by injection molding, and the bending elastic modulus under dry conditions and water absorption conditions, and its retention rate, low temperature (-
The Izod impact strength, surface gloss, scratch resistance (Rockwell hardness), stress cracking resistance, and electrification property (surface specific resistance) at 30 ° C. were measured. The results are shown in Table 2.

Table 1 Composition (parts by weight) Example 1 Example 2 Example 3 Example 4 Ny6 65 65 65 65 CMPP 15 20 5 10 CMEBR 20 15 30 15 PP − − − 10

Composition (parts by weight) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Ny6 100 80 70-CMEBR-20 30-HDPE ---- 100

Table 2 Physical Properties Example 1 Example 2 Example 3 Example 4 Flexural modulus retention (%) ⁽¹⁾ 80 80 80 80 Izod impact strength ⁽²⁾ −30 ° C. 70 60 75 60 Surface Gloss (Gloss) ⁽³⁾ 90 90 90 90 Rockwell hardness ⁽⁴⁾ 96 96 90 90 Stress cracking resistance (with or without cracks) ⁽⁵⁾ No No No No Surface resistivity ⁽⁶⁾ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰

Table 2 (continued) Physical property Comparative Example 1 Comparative example 2 Comparative Example 3 Comparative Example 4 Flexural modulus retention (%)⁽¹⁾ 30 40 50 100 Izod impact strength⁽²⁾ -30 ℃ 3 15 20 15 Surface gloss (Gloss value)⁽³⁾ 95 85 70 60 Rockwell hardness^(Four) 120 90 85 30 Stress cracking resistance (presence of cracks)^(Five) No No No Yes Surface resistivity⁽⁶⁾ Ten^Ten Ten¹¹ Ten¹² Ten¹⁷ 

(1) Flexural modulus: at 23 ° C., ASTM D790
Measured under dry conditions and under water absorption conditions (when the test piece was immersed in warm water at 40 ° C to absorb water up to the equivalent of 50% RH saturated water absorption), and the retention rate was measured (unit:
kg / cm ² ). (2) Izod impact strength: Measured by ASTM D256 at -30 ° C (unit: kg · cm / cm). (3) Surface gloss: Measure gloss value at 60 ° by ASTM D523
(Units%) . (4) Rockwell hardness: measured by ASTM D758 R scale (unit is R). (5) Stress cracking resistance: Fix one end of a sheet of 20 mm × 200 mm × 3 mm and apply a load of 500 g to the other end,
Apply a surfactant to the center and observe for cracks. (6) Surface specific resistance: Measured by ASTM D257 for a sheet of 80 mm × 80 mm × 3 mm (unit: Ω).

As is clear from Table 2, Examples 1 to 4
The composition (1) had good flexural modulus retention under water absorption conditions, good impact resistance at low temperatures, good scratch resistance and stress cracking resistance, good surface gloss, and low surface specific resistance. In contrast, the composition of each comparative example was significantly inferior in at least one of the above values.

[0066]

As described in detail above, the composition for ski boots of the present invention contains a polyamide resin, a modified polyolefin, and a modified olefin elastomer within respective specific ranges. It has excellent mechanical strength, impact resistance at low temperature, scratch resistance and stress cracking resistance, and has a good surface gloss and is difficult to be charged.

Such a composition of the present invention is extremely suitable as a resin for ski boots.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yukihiko Yagi 3-1, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Tonen Kagaku Co., Ltd. Technology Development Center

Claims (1)

[Claims] 1. (a) 50 to 90% by weight of polyamide resin,
(b) a modified polyolefin, or 2 to 40% by weight of a polyolefin resin composition containing 1% by weight or more of the modified polyolefin, and (c) a modified olefin elastomer,
Or 1% by weight of the modified olefin elastomer
A composition for ski boots, comprising 2 to 40% by weight of the olefin elastomer composition contained above.