JPH03234755A - Thermoplastic elastomer composition excellent in adhesive power - Google Patents

Abstract

PURPOSE:To improve moldability, adhesion to a polar resin, and rubberlike characteristics by compounding two specific hydrogenated block copolymers and a thermoplastic polyurethane elastomer. CONSTITUTION:A block copolymer comprising 0-50wt.% polymer block A mainly consisting of a vinylarom. compd. and 100-50wt.% polymer block B mainly consisting of a conjugated diene compd. is hydrogenated to give a hydrogenated block copolymer (a) having a number-average mol.wt. of 80000 or higher. Separately, a hydrogenated block copolymer having a number-average mol.wt. of 30000-100000 and obtd. by hydrogenating a block copolymer comprising the polymer block a and polymer block B is combined with a molecular unit having a carboxylic acid (deriv.) group to give a modified hydrogenated block copolymer (b). 100 pts.wt. block copolymer (a), 10-200 pts.wt. block copolymer (b), and 10-250 pts.wt. thermoplastic polyurethane elastomer are compounded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention combines a hydrogenated block copolymer having a number average molecular weight of 80,000 or more, a thermoplastic polyurethane elastomer, and an acid-modified hydrogenated block copolymer. The present invention relates to a thermoplastic elastomer composition that firmly adheres to a resin having a polar group without using an adhesive, and has excellent oil resistance, rubber properties, and moldability. .

[Prior art] Conventionally, different types of materials have been bonded together to form a laminate, giving the advantages of both materials, or the same material sandwiching different types of materials to form a laminate. There have been attempts to produce laminates that compensate for the deficiencies of one material or the other. Particularly recently, attempts have been made to laminate rubber onto plastic in order to improve the cheap feel and poor feel of plastic. Laminated products made of this rubber are soft to the touch, have a good feel, have a luxurious feel, and have excellent soundproofing and vibrationproofing properties, making them suitable for automobile interior parts and home appliance parts. Thermoplastic resins used as materials for such laminates include polyethylene, polypropylene,
Ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyvinyl chloride, polyethylene terephthalate, nylon, polycarbonate, polystyrene, high-impact polystyrene, polyvinylidene chloride, ABS
resin, etc. are used.

These laminates are used in the form of sheets, films, molded products with complex shapes, and the like.

These laminates are generally produced by bonding the same or different materials using an adhesive, or by coextrusion or multilayer molding without using an adhesive.

However, depending on the type of laminated materials or their combination, sufficient adhesive effects may not be obtained.
In particular, when obtaining a laminate by a coextrusion method or a multilayer molding method that does not use an adhesive, materials that do not have mutual adhesiveness cannot be used.

Therefore, when obtaining a laminate of mutually non-adhesive materials using a coextrusion method, a method is used in which a material with adhesive properties is used for both materials as an adhesive layer, such as ethylene-vinyl acetate copolymer. Polymers, ionomer resins, styrene-butadiene block copolymers, etc. are used. However, these resins also have problems such as not necessarily being able to obtain a sufficient adhesive effect depending on the type of material to be coextruded, and having poor adhesive strength, water resistance, etc. Generally speaking, it is difficult to use an adhesive layer in the case of injection molded products with multiple shapes, and the current situation is that the multilayer molding method can only be used in limited combinations that have adhesive properties.

In order to solve these problems, a more advanced technology was disclosed in Japanese Patent Publication No. 13911/1983, in which a thermoplastic polymer having a polar group was added to an acid-modified hydrogenated block copolymer. ing. The laminate described in this publication exhibits excellent adhesion to polar resins, glass, metals, etc., and is an effective method, but depending on the combination of compositions, fluidity may be poor, and molding into complex shapes is difficult. The problem is that it is difficult to obtain products.

Further, JP-A-63-254156M discloses a composition in which a thermoplastic polyurethane is blended with an acid-modified hydrogenated block copolymer. However, although the composition described in this publication exhibits excellent properties such as mechanical strength and adhesion with other resins, and is a useful composition, its moldability may be poor, and rough improvements are desired. .

Further, JP-A-64-33201 discloses a composition comprising a thermoplastic polyurethane having a specific viscosity and a non-hydrogenated block copolymer or a hydrogenated block copolymer. However, the composition described in this publication has poor compatibility with the thermoplastic polyurethane and the non-hydrogenated or hydrogenated block copolymer, resulting in low mechanical strength and the problem of peeling of the molded product, which requires further improvement. desired.

[Problem to be solved by the invention]

The present invention was made in view of the above points, and is a thermoplastic elastomer that has excellent molding processability such as injection molding and extrusion molding, has high adhesiveness with polar resins, and also has excellent rubber properties. The object of the present invention is to provide a thermoplastic elastomer composition particularly suitable for multilayer molding applications.

[Means to solve the problem]

The present invention provides the following methods: (a) Hydrogenation of a block copolymer consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one conjugated diene compound. The number average molecular weight obtained by
(b) 100 parts by weight of a hydrogenated block copolymer of 10,000 or more, and (b) a polymer block A mainly composed of at least one vinyl aromatic compound, and a polymer block B mainly composed of at least one conjugated diene compound. Modified hydrogenated block copolymers 10 to 20 in which a molecular unit containing a carboxylic acid group or a derivative group thereof is bonded to a hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of
The present invention provides a thermoplastic elastomer composition which essentially comprises three components (a), (b), and (c): 0 part by weight and (c) a thermoplastic polyurethane elastomer from 10 to 250 parts by weight.

The present invention will be described in detail below.

The block copolymer before hydrogenation of the hydrogenated block copolymer used as component (a) of the present invention includes at least one vinyl aromatic compound polymer block, preferably two or more, and a conjugated diene compound. It contains at least one polymer block mainly composed of. Here, the polymer block mainly composed of conjugated diene has a weight ratio of vinyl aromatic compound to conjugated diene compound of O/100 to 50/
50. It is preferably a polymer block with a composition range of O/100 to 40/60, and the distribution of the vinyl aromatic compound in this block is a random taper (monomer component increases or decreases along the molecular chain).
, partially block-shaped, or any combination thereof.

In the block copolymer before hydrogenation, the weight ratio of the vinyl aromatic compound content to the conjugated diene compound content is preferably in the range of 10/90 to 90/10, and when rubber-like texture is required. The preferred range is 15/85 to 60/40.

The vinyl aromatic compounds constituting the block copolymer before hydrogenation include styrene, α-methylstyrene, 1,
One or more types are selected from 1-diphenylethylene, paramethylstyrene, vinyltoluene, etc., and styrene is particularly preferred. The conjugated diene compound is selected from one or more of butadiene, isoprene, 1,3-pentadiene, etc., and butadiene and/or isoprene are particularly preferred.

Furthermore, when butadiene is used as a conjugated diene compound in the block copolymer before hydrogenation, the amount of 1,2 bonds in the microstructure of the butadiene moiety is preferably in the range of 10 to 80%, and A range of 50% is particularly preferred.

When the block copolymer before hydrogenation contains two or more blocks mainly composed of vinyl aromatic compound blocks or conjugated diene compounds, each block may have the same structure or may have different structures. There may be. Further, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial, or a combination thereof.

The number average molecular weight of the hydrogenated block copolymer used as component (a) of the present invention is 80,000 or more, preferably 100,000 or more. By using a hydrogenated block copolymer having a number average molecular weight of 80,000 or more, a composition having excellent physical properties such as oil resistance and compression set can be obtained.

Further, the molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) is preferably in the range of 10 or less, more preferably 5
It is as follows.

The number average molecular weight and molecular weight distribution of the hydrogenated block copolymer can be easily determined by gel permeation chromatography or the like.

The hydrogenated block copolymer provided in the present invention may be obtained by any production method as long as it has the above-described structure. For example, Tokko Sho 140-237
A vinyl aromatic compound-conjugated diene compound block copolymer is synthesized in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 8704/1988, and then by a known method such as Japanese Patent Publication No. 42-8704, The aromatic compound of the vinyl aromatic compound block A is hydrogenated in an inert solvent in the presence of a hydrogenation catalyst according to the methods described in Publications No. 63-4841 and Japanese Patent Publication No. 1-53851. A hydrogenated block copolymer is synthesized in which not more than 20% of the double bonds and at least 80% of the aliphatic double bonds of the conjugated diene compound block B are hydrogenated.

The degree of unsaturation of block B as used in the present invention refers to the proportion of carbon-carbon double bonds contained in block B, which is determined by nuclear magnetic resonance absorption spectrum (NMR), infrared absorption spectrum (IR) It is measured by instrumental analysis such as, chemical analysis such as iodometry.

Next, the acid-modified hydrogenated block copolymer used as component (b) of the present invention will be explained.

The hydrogenated block copolymer that is the basis of the acid-modified hydrogenated block copolymer used as component (b) of the present invention is (a
It has the same polymer structure as component ), but among these, those with a number average molecular weight of 30,000 to 100,000, more preferably 35,000 to 70,000, have particularly excellent fluidity. By using a polymer having a number average molecular weight within this range, the moldability and physical properties of the composition of the present invention will be well-balanced and excellent.

Component (b) of the present invention is a hydrogenated block copolymer in which a molecular unit containing a carboxylic acid group or a derivative group thereof is bonded. Examples of compounds containing such carboxylic acid groups or derivative groups thereof include maleic acid, halogenated maleic acid, itaconic acid, cis-4-cyclohexene-1
, 2-dicarboxylic acid, endo-cis-bicyclo(2,2
, 1) -5-hebutene-2,3-dicarboxylic acid, etc., anhydrides, esters, amides, imides, etc. of these dicarboxylic acids, and acrylic acid, methacrylic acid, crotonic acid, etc., and esters of these monocarboxylic acids, such as methacrylic acid. Examples include derivatives such as methyl acid, glycidyl methacrylate, and amides. Among these, maleic anhydride is particularly preferred.

The amount of the compound containing a carboxylic acid group or its derivative group is about 20 parts by weight or less, preferably 1 part by weight or less.
The amount is 0 parts by weight or less, preferably 5 parts by weight or less.

By using component (b) in which a carboxylic acid group or a derivative group thereof is introduced into a hydrogenated block copolymer, the compatibility of components (a) and (c) of the present invention is significantly improved,
Although the adhesion of the composition of the present invention to a resin having a polar group is improved and the mechanical properties are also improved, if the amount of carboxylic acid group or its derivative group added is too large, the fluidity of the composition will decrease. , a problem arises in which molding processability deteriorates. For this reason, the amount of addition described above is desirable.

The amount of component (b) used in the present invention is as follows: (a) in the present invention.
The amount ranges from 10 to 200 parts by weight per 100 parts by weight of the component. If the amount of component (b) used is less than 10 parts by weight, the compatibility improving effect will not be sufficient and a desirable composition will not be obtained. Furthermore, even if a large amount exceeding 200 parts by weight is used, the compatibility improvement effect reaches a plateau, and on the contrary, the fluidity decreases markedly, resulting in a composition that is no longer desirable. For this reason, the above-mentioned range is preferable. Roughly desirable range is 20-1
00 parts by weight.

Next, the thermoplastic polyurethane elastomer used as component (c) of the present invention will be explained.

The thermoplastic polyurethane elastomer used as component (c) of the present invention is obtained by addition polymerizing a long chain glycol and a short chain glycol having active hydrogen at both ends using a diisocyanate compound. Although there are no particular limitations, typical long-chain glycols include polyester, polyether, and polycarbonate. Specific compound names include polyester-based dehydrated condensates of adipic acid and various glycols, such as poly(ethylene adipate), poly(diethylene adipate), poly(1,4-butylene adipate), and poly(1,4-butylene adipate). . Examples include poly(1,6-hexamethylene glycol carbonate).

Polyolefin glycols are also useful, and polybutadiene diol, polyisoprene diol, and hydrogenated products thereof are preferably used.

Typical examples of short-chain glycols include aliphatic glycols and aromatic glycols, and examples of aliphatic glycols include ethylene glycol, 1,3-propylene glycol, and 1,4-propylene glycol. Examples include -butane glycol, 1,3-butane glycol, 1,5-pentane glycol, 1,6 hexane glycol, etc. Examples of aromatic glycols include bisphenol A1 hydroquinone diethylol ether, bisphenol A
/ethylene glycol, etc. can be exemplified.

Diisocyanates include aromatic, alicyclic, and aliphatic diisocyanates, such as tolylene diisocyanate, xylylene diisocyanate, 4,4 diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate,
Examples include hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated products of xylylene diisocyanate and 4.4°-diphenylmethane diisocyanate.

The thermoplastic polyurethane elastomer used as component (c) of the present invention is classified into fully thermoplastic type and incompletely thermoplastic type depending on its synthesis conditions. These are determined by the molar ratio of the difunctional long-chain glycol to short-chain glycol 0 group and the diisocyanate NGO group of the raw materials, and are approximately 0.
．． The completely thermoplastic type is synthesized when 95<NGO10 days≦1, and the incompletely thermoplastic type is synthesized when about 1<N0010 days<1.1. Either of these can be used as component (c) in the present invention.

The amount of component (c) used in the present invention is 10 to 250 parts by weight per 100 parts by weight of component (a). If the amount used is less than 10 parts by weight, the adhesion with the resin having a polar group will be unsatisfactory, and if it is used in a large amount exceeding 250 parts by weight, the improvement in adhesion will reach a plateau, and conversely, the adhesion with the resin having a polar group will be unsatisfactory. This results in deterioration of physical properties such as distortion, deterioration of water absorption, and increase in cost, making it impossible to obtain a desirable composition.

A generally desirable amount is in the range of 40 to 150 parts by weight.

The composition of the present invention may preferably contain oil in addition to the above-mentioned essential components. Oil is a useful additive for imparting flexibility and processability to the resulting composition as well as for improving economic efficiency. The oil used in the present invention is a non-aromatic rubber oil, such as a diluent oil for rubber classified into paraffinic and naphthenic oils, which are generally known as mineral oil softeners. Of these, paraffinic oils are preferred, and even among paraffinic oils, 5% of the aromatic ring component is
The following are desirable. The amount of oil used should be kept within a range that does not impair the physical properties of the resulting thermoplastic elastomer composition, but as a rough guide, it should be between O and 200 parts by weight per 100 parts by weight of the hydrogenated block copolymer. be.

Additionally, a thermoplastic resin, preferably a polyolefin resin, can be added to the composition of the invention.

Polyolefin resins are useful in improving processability, mechanical strength, etc. of thermoplastic elastomer compositions, and examples of polyolefin resins include polyethylene, polypropylene, polybutene resins, propylene and ethylene,
- Block copolymers and random copolymers with α-olefins such as butene can be used. Note that the amount of polyolefin resin used should be kept within a range that does not reduce the flexibility of the resulting thermoplastic elastomer composition, but as a rough guide, hydrogenated block copolymer 100
Weight range: 0 to 150 parts by weight. Additionally, an inorganic filler can be added to the composition of the present invention.

Inorganic fillers are useful for increasing the hardness of the resulting thermoplastic elastomer composition and improving economic efficiency as an extender.

As the inorganic filler, for example, calcium carbonate, talc, clay, synthetic silicon, titanium oxide, carbon black, barium sulfate, etc. can be used. The amount of inorganic filler used should be kept within a range that does not impair the flexibility of the resulting thermoplastic elastomer, but as a rough guide, it is O to 10 parts by weight per 100 parts by weight of the hydrogenated block copolymer.
It is approximately 0 parts by weight.

Furthermore, in addition to the above-mentioned components, the composition of the present invention includes a lubricant,
Light stabilizers, pigments, flame retardants, antistatic agents, silicone oil, antiblocking agents, ultraviolet absorbers, oxidative deterioration inhibitors, and the like may be added as appropriate.

The method of mixing the composition of the present invention includes an extruder, a roll,
A conventional method used for kneading rubber such as a Banbury mixer can be used, and as a molding method, extrusion molding, injection molding, blow bottom molding, etc. can be used.

The thermoplastic elastomer composition obtained by the present invention is
Resins having polar groups, such as polyester resins, polyamide resins, polycarbonate resins, polyphenylene sulfide resins, polyacrylate resins, polymethacrylate resins, polyether resins, acrylonitrile/styrene resins, acrylonitrile/styrene/ It has adhesive properties with butadiene resins, vinyl chloride resins, vinylidene chloride resins, phenolic resins, epoxy resins, etc., and has excellent moldability, oil resistance, mechanical properties, heat resistance, etc., so it is multi-layered. It can be used in a wide range of applications such as processing materials for molded objects.

[Examples] Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples.

Note that the physical properties used in the Examples and Comparative Examples were measured by the following test methods.

(1) Peel strength (Kl/25#1I11 > JIS-
Compliant with 180 degree peeling described in -6854.

[2) Immersion test (weight %) Based on υIS-K-6301, the weight change was measured after 2 hours at 70°C in JIS-3 oil.

(3) 611 degree JIS-6301A type (4) Tensile strength (K'j/cai) Sample is 2! f
J I S − using an injection sheet of yI thickness
It was used as a No. 3 test piece described in K-6301.

Measurement is based on JIS-K-6301.

(5) Elongation (%) Compliant with JIS-K-6301.

(6) Compression set (%) Based on JIS-K-6301, 10°C, 22
Measured in the distance of time.

(7) Quality of Li-shaped products The amount of molding was visually observed and evaluated using the following scale.

○: The entire surface of the rli-shaped product is smooth and smooth.

Δ: 70-marks were generated on a part of the surface of the molded product, and there were parts that were not smooth.

X: Flow marks occur on the entire surface of the molded area, and the surface is rough.

Further, hydrogenated block copolymers, thermoplastic urethane elastomers, modified hydrogenated block copolymers, and polar resins used in Examples and Comparative Examples are summarized in Tables 1 to 4. The number average molecular weight and weight average molecular weight were measured using gel permeation chromatography using standard polystyrene as a reference.

Examples 1 to 4, Comparative Examples 1 to 3 Hydrogenated block copolymers selected from Tables 1 to 3, thermoplastic polyurethane elastomers, and modified hydrogenated block copolymers were mixed in the amounts listed in Table 5. , PW-380 (manufactured by Idemitsu Kosan Co., Ltd.) as a paraffin oil was added in the amount shown in Table 5 and impregnated into the mixture.
To 100 parts by weight of the oil-extended mixture, 0.2 parts by weight of Irganox 1010 (manufactured by Ciba-Geigi), 0.3 parts of calcium stearate, and 0.0 parts of polyethylene wax were added.
3 parts were added.

Next, this is powdered using twin-screw extrusion IJiPcM-30 (manufactured by Ikegai Iron Works), and then an in-line screw type injection molding machine is used at an injection pressure of 5 ONg/i and an injection temperature of 170 to 19
200 layers x 200mX under the conditions of 0℃ and mold temperature 55℃
A flat plate sample with a thickness of 4ai was prepared. In the mold, one of the ABS resins selected from Table 4 as a resin having a polar group was used.
A test piece of 50 g x 25 si

Also, under the same injection conditions, 1501nIIIx 150 #
lX 2! A flat plate sample with a thickness of R1R was molded and used as a test piece for measuring physical properties. Various physical properties were measured using predetermined methods, and the results are listed in Table-5.

As is clear from Examples 1 to 4 and Comparative Examples 1 and 2, when a hydrogenated block copolymer with a number average molecular weight of less than 80,000 was used, the compression set of the resulting composition deteriorated significantly. However, it is not desirable.

Furthermore, as shown in Comparative Example 3, when the hydrogenated block copolymer having a number average molecular weight of 80,000 or more, which is the component (a) of the present invention, is not used, the moldability of the resulting composition is poor and the composition is rough. It can be seen that the compression set is also extremely poor.

Examples 5 to 10, Comparative Examples 4 to 7 Hydrogenated block copolymers, thermoplastic polyurethanes, and modified hydrogenated block copolymers selected from Tables 1 to 3 were combined with PW-380 (Idemitsu Kosan Co., Ltd.) as paraffin oil. Asahi Bolipro E-1100 (manufactured by Asahi Kasei Corporation) as polypropylene and calcium carbonate in the amounts shown in Table 6 were mixed, and the adhesion to ABS resin was evaluated in the same manner as in Example 1.

The measurement results are summarized in Table-6.

As is clear from Examples 5 to 7 and Comparative Examples 4 and 5, the composition of the present invention using an appropriate amount of thermoplastic polyurethane elastomer has a desirable composition with excellent physical properties such as oil resistance, compression set, and moldability. It turns out that it is a thing. -5 When thermoplastic polyurethane elastomer is not used (Comparative Example 4)
> has poor physical properties such as adhesion to ABS resin and oil resistance, and conversely, when used in too large a quantity (Comparative Example 5), it may cause a decrease in physical properties such as compression set and a decrease in the quality of the molded product. It turns out that this is not a desirable invitation.

Furthermore, as is clear from Example 8.9 and Comparative Examples 6 and 7, the composition of the present invention using an appropriate amount of the modified hydrogenated block copolymer improves the quality of molded products, adhesiveness, compression set, etc. It can be seen that this is a desirable composition with excellent properties. On the other hand, when the modified hydrogenated block copolymer is not used (Comparative Example 6), the dispersibility of the composition is poor and peeling occurs in the molded product, and the adhesion to ABS resin deteriorates, which is not desirable. On the other hand, if too large a quantity is used (Comparative Example 7), the physical properties such as compression set of the resulting composition may deteriorate, and the quality of the molded product may deteriorate extremely. It has become clear that this makes the composition less desirable.

Examples 11-15, Comparative Examples 8-12 Examples 11-15 used the composition of Example 6, while Comparative Examples 8-12 used the composition of Comparative Example 4 in the same manner as Example 1. Tested. Various resins having polar groups fixed in the mold were tested, and the peel strength measurement results are listed in Table 7.

As is clear from the comparison of Examples 11 to 15 and Comparative Examples 8 to 12, the compositions of the present invention are desirable compositions with significantly improved adhesive strength to resins having various polar groups.

〔Effect of the invention〕

The elastomer composition of the present invention exhibits excellent adhesion to resins having polar groups, has low adhesion to molds, etc. during molding, and has excellent mold releasability. extrusion,
It can be used extremely effectively in fields such as multilayer molding. For this reason, automobile interior parts, home appliance parts, sporting goods,
It is widely used for miscellaneous goods, etc., and has great industrial significance.

(Margin below)

Claims (1)

[Claims] 1. (a) A block copolymer consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one conjugated diene compound. The number average molecular weight obtained by hydrogenating the coalesce is 8
(b) 100 parts by weight of a hydrogenated block copolymer of 10,000 or more, and (b) a polymer block A mainly composed of at least one vinyl aromatic compound, and a polymer block B mainly composed of at least one conjugated diene compound. 10 to 200 parts by weight of a modified hydrogenated block copolymer in which a molecular unit containing a carboxylic acid group or a derivative group thereof is bonded to a hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of ( c) Thermoplastic polyurethane elastomer 10
A thermoplastic elastomer composition containing up to 250 parts by weight of three components (a), (b), and (c).