JPS5931461B2 - Method for manufacturing thermoplastic resin laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermoplastic resin laminate, and more particularly, to a method for producing a laminate comprising a polyolefin layer and a polybutylene terephthalate layer, both of which are firmly adhered. It is.

Polybutylene terephthalate has excellent properties such as excellent rigidity and gas barrier properties, and good transparency and gloss even in an unstretched state, so it is used in fields such as food and pharmaceutical containers and packaging materials. considered for use.

However, polybutylene terephthalate has poor heat-sealability, so its use has been severely limited, particularly in the field of packaging films. Conventionally, in order to impart heat-sealability to polyester films, a method has been used in which thermoplastic resins with good heat-sealability, such as polyolefin, are laminated. However, polyolefin and polyester have poor affinity and cannot be bonded together by normal molding. Currently, in the dry lamination method and extrusion lamination method that are mainly used to obtain laminated films, an organic metal primer such as an organic titanate or an organic aluminum compound or a urethane adhesive is interposed between the polyolefin layer and the polyester layer. and/or the substrate is bonded with corona,
Methods such as treating with ultraviolet rays, flame, etc. and laminating them are used. On the other hand, the coextrusion method has so far been used exclusively for biaxially oriented polyethylene terephthalate as a polyester, and has rarely been proposed. Only methods have been proposed in which the layer is intermixed with one of the polybutylene terephthalate layers. However, this method of mixing ionomer resins is difficult because (a) even if the ionomer resin is alone, the adhesion to polybutylene terephthalate is poor;
Polyester does not have very good compatibility with any layer,
In addition, the different melting behavior caused uneven extrusion, so it could not be put to practical use. The purpose of the present invention is to co-extrude polyolefin and polybutylene terephthalate to produce a laminate.
The object of the present invention is to provide a method for obtaining a laminate in which the disadvantages of the above-mentioned methods are improved, in particular in which a polyolefin layer and a polybutylene terephthalate layer are bonded more strongly.

In producing a laminate consisting of polyolefin and polybutylene terephthalate, the present applicant previously discovered that a modified polyolefin in which part or all of the polyolefin was grafted with at least one monomer selected from unsaturated dicarboxylic acids or derivatives thereof. It was discovered and proposed that a laminate with relatively good adhesiveness can be obtained by using polyolefin.

(Patent Application No. 1983-108014, Special Publication No. 1983-44822)
The present invention is based on the discovery that, in the above method, when the above-mentioned polyester copolymer is further blended with polybutylene terephthalate, a laminated structure with excellent interlayer adhesion can be obtained. It is.

That is, in the present invention, when producing a laminate consisting of a polyolefin layer and a polybutylene terephthalate layer by melting polyolefin and polybutylene terephthalate and coextruding both resins from one die, the polyolefin layer is partially or consists entirely of a modified polyolefin grafted with at least one monomer selected from unsaturated dicarboxylic acids or derivatives thereof,
and the polybutylene terephthalate layer comprises (a) 60 to 95 parts by weight of polybutylene terephthalate; and (b)
A dicarboxylic acid component of which 90 mol% or more is terephthalic acid, and a general formula HO(CH2CH2O).

X mol% (12/
/n)≦(X)≦(15C/n) ・・・・・・・・・
(1) Polyester copolymer 40 or 40 having a glycol component consisting of (where x is mol% of ether glycol in the total glycol) and mol% of alkylene glycol (100-X) having 6 or less carbon atoms. 5 parts by weight of a thermoplastic resin laminate.

The polybutylene terephthalate used in the method of the present invention is a polyester mainly containing tetramethylene glycol as a diol component and terephthalic acid as a dicarboxylic acid component, but a part of this component is used as a diol, such as ethylene glycol, trimethylene, etc. Glycol, decamethylene glycol, etc., in which 85 mol% or more of butylene terephthalate is substituted with dicarboxylic acid such as isophthalic acid, hexahydroterephthalic acid, diphenyl dicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, etc. as a unit. It may be made of polyester.

It may also be mixed with a small amount of other polyester. The polyester copolymer used in the laminate of the present invention is a dicarboxylic acid component whose 90 mol% or more is terephthalic acid and an ether represented by the general formula HO(CH2CH2O)NH (where n is an integer from 2 to 6). It is a polyester copolymer whose constituent components are glycol and a glycol component consisting of alkylene glycol having 6 or less carbon atoms.

Other dicarboxylic acid components used in an amount of 10 mol% or less include, for example, phthalic acid, isophthalic acid, hexahydroterephthalic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, and the like.

The dicarboxylic acid component needs to consist of terephthalic acid in an amount of 90 mol % or more; if it is less than 90 mol %, the heat resistance of the polyester copolymer will be poor and the heat resistance of the polybutylene terephthalate will be lowered, which is not preferable. Next, the ether glycol represented by the general formula HC(CH2CH2O)NH (where n is an integer from 2 to 6) specifically refers to diethylene glycol, triethylene glycol, and polyethylene glycol having 4 to 6 (CH2CH2O) repeating units. say.

Among these, diethylene glycol and triethylene glycol are preferred. Alkylene glycol having 6 or less carbon atoms specifically includes ethylene glycol, 1,3-
Propylene glycol, tetramethylene glycol, decamethylene glycol Hexamethylene glycol. In the polyester copolymer used in the present invention, the ether glycol represented by the above general formula HO(CH2CH2O)NH satisfies the following O composition in all glycols constituting the polyester copolymer in X mol% (12/n) (X) (150/n) (where X is the mol% of ether glycol in all glycols).

Specifically, in the case of n-2 diethylene glycol, diethylene glycol is 6 to 75 mol%, preferably 1
It needs to be in the range of 2 to 60 mol%, and n
In the case of triethylene glycol with =3, it is necessary that the triethylene glycol is 50 mole %, preferably in the range of 8 to 40 mole %. If the molar ratio of ether glycol is below the above range, the effect of improving the adhesion of the polybutylene terephthalate layer to the polyolefin layer will be poor, while if it exceeds the above range, the heat resistance of the polyester copolymer will be extremely reduced, and the polybutylene terephthalate This results in a significant decrease in heat resistance. The polyester copolymer used in the present invention can be produced by various methods commonly used for producing polyethylene terephthalate.

For example, methods include polycondensation of terephthalic acid and alkylene glycol or ether glycol by direct esterification, or polycondensation of dialkyl or diglycol ester of terephthalic acid with alkylene glycol or ether glycol by transesterification. You can take it. In the laminate of the present invention, the blending ratio of the polyester copolymer to polybutylene terephthalate is 5 to 40 parts by weight, preferably 10 to 3 parts by weight, based on 95 to 60 parts by weight of polybutylene terephthalate.
It must be in the range of 0 parts by weight. If the amount is less than this range, sufficient effects will not be obtained, and if it is too much, the excellent properties of polybutylene terephthalate, such as heat resistance, rigidity, and chemical resistance, will be poor. The polybutylene terephthalate composition may also contain stabilizers, lubricants, antistatic agents, antiblocking agents, slip agents,
It may contain pigments, fillers, such agents, and the like. The polyolefin used in the present invention is a crystalline homopolymer of olefin monomers such as ethylene, propylene, 1-butene, 1-hexene, 3-methyl-1-benzene, and 4-methyl-1-benzene. or a copolymer, e.g.
High density polyethylene, medium density polyethylene, low density polyethylene, polypropylene Ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-
Refers to hexene copolymers, propylene-1-butene copolymers, and mixtures thereof.

Among these, it is preferable to use low-density polyethylene and ethylene-propylene copolymer, which are easy to obtain transparent laminates. In the method of the present invention, the polyolefin is a partially or fully unsaturated dicarboxylic acid or a derivative thereof (
(hereinafter referred to as graft monomer).

In the present invention, unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, etc., and unsaturated dicarboxylic acid derivatives include acid anhydrides, esters, amides,
imides, such as maleic anhydride, itaconic anhydride,
Citraconic anhydride, maleic acid monomethyl ester, maleic acid dimethyl ester, fumaric acid monomethyl ester fumaric acid dimethyl ester, maleic acid monoamide,
Malei-4 diamide, Malei-4-N-monoethylamide, Maleic acid-N,N-diethylamide, Maleic acid-
N-monobutylamide, maleic acid-N,N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, 7-malic acid-N,N-diethylamide, fumaric acid-N-monobutyl Examples include amide, fumaric acid mono-N,N-dibutylamide, maleimide, N-butylmaleimide, and N-phenylmaleimide. Among these, maleic anhydride and fumaric acid are most preferred. In the present invention, the amount of graft monomer contained in the polyolefin by grafting must be in the range of 10-4 to 4% by weight, preferably 10-3 to 1% by weight.

If it is less than 10-4% by weight, the adhesion to polybutylene terephthalate will be insufficient, while if it is more than 4% by weight, the adhesion to polybutylene terephthalate and thermal stability will decrease.

The modified polyolefin used in the present invention exhibits excellent adhesive strength even by grafting only a small amount of graft monomer, so its heat sealability, thermal stability, and moldability are almost the same as those of unmodified polyolefin, and it is usually It has the feature that it can be used in the same concept as polyolefin. Various known methods can be employed to graft the graft monomer onto the polyolefin. For example, it is carried out by heating the polyolefin, the grafting monomer, in the presence or absence of a solvent, with or without the addition of a radical initiator, at elevated temperatures. Other vinyl monomers such as styrene may be present during the reaction.
The polyolefin used in the present invention may be partially or completely modified, but the concentration of the graft monomer in the resin can be easily adjusted. By this, a modified polyolefin to which a graft monomer is grafted at a high concentration is produced in advance, and then the modified polyolefin is mixed with the unmodified polyolefin,
A method in which the total amount of graft monomer is 10@-4 to 4% by weight is preferred. The modified polyolefin of the present invention may further contain stabilizers, anti-locking agents, pigments, fillers, etc. to the extent that performance is not impaired. Next, in order to laminate the polyolefin and polybutylene terephthalate compositions, a method is used in which both resins are melted in separate extruders and coextruded through a single die.

In the method of the present invention, it is particularly preferable to employ a method in which the polyolefin layer and the polybutylene terephthalate composition layer are coextruded in a state in which they are bonded together in a die. During coextrusion, the resin temperature of the polyolefin should be in the range of 190°C to 300°C, while the resin temperature of the polybutylene terephthalate composition should be in the range of 23°C to 300°C. At temperatures lower than this range, coextrusion is very difficult, and at higher temperatures, the resin may decompose. The temperature difference between both resins is small because both resins are co-extruded from one die.
Both resins are preferably laminated at a temperature in the range of 235°C to 27°C. To obtain transparent laminates of polyolefin, polybutylene terephthalate compositions, rapid cooling of the coextruded resin is required. In addition,
The laminate obtained by the present invention is not limited to two layers, but can have a sandwich structure in which a polybutylene terephthalate layer is used as an intermediate layer and the polybutylene terephthalate layer is sandwiched between polyolefins, or a laminate in which the polyolefin layer and polybutylene terephthalate layer are reversed. It is also possible to laminate another polyolefin layer on top of the polyolefin layer to form a three-layer structure.

The method of the present invention can be applied to the molding of multilayer blown films, multilayer sheets, multilayer blowing, multilayer pipes, and the like.

The thus obtained laminate of polyolefin and polybutylene terephthalate is transparent, has excellent rigidity and gas barrier properties, and is heat sealable.
It is useful for packaging materials for fresh foods such as vegetables, meat, fish, eggs, etc., containers for alcohol, soft drinks, fruit juices, liquid seasonings, etc., and containers for liquid medicines such as eye drops and athlete's foot medicine. be.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. Example 1 5 parts by weight of high-density polyethylene (manufactured by Mitsui Petrochemicals, Izexx 1300J) grafted with 2% by weight of maleic anhydride and 95 parts by weight of low-density polyethylene (Mitsui Polychemicals, Mirason M-50) were added. The mixture was melt mixed in an extruder and fed to a two-layer film die at a resin temperature of 23°C.

On the other hand, the intrinsic viscosity (1%, o-chlorophenol, 25.
C) = 90 parts by weight of polybutylene terephthalate of 0.90, dimethyl terephthalate, ethylene glycol,
Intrinsic viscosity (o-chlorophenol, 1%, 25°C) manufactured by polycondensation reaction of three components of diethylene glycol using tetrabutoxy titanate as a catalyst.
- 0.85, the molar ratio of ethylene glycol and diethylene glycol of the glycol components constituting the copolymer is 6
A mixture of 0:40 polyester copolymer chips with 10 parts by weight was melted in a separate extruder and fed to the die at a resin temperature of 250°C. The adhesive strength of the laminated film obtained by coextruding in this way and rapidly cooling with a cooling roll at 30°C was 66.
It was a hot plate. In addition, the adhesive strength is 2.
5 (V 7l
n) This is a value measured at a chuck speed of 5011 m1/min. Comparative Example 1 A laminated film was obtained in the same manner as in Example 1 except that low-density polyethylene without modified polyethylene was used, but the low-density polyethylene-polybutylene terephthalate layer was not tightly bonded. .

Example 2 5 parts by weight of high-density polyethylene (Mitsui Petrochemical Co., Ltd., Izex 1300J) grafted with 2% by weight of maleic anhydride and high-density polyethylene (Mitsui Petrochemical Co., Ltd., Izex 1300J)
A high-density polyethylene-polybutylene terephthalate laminated film was obtained in the same manner as in Example 1, except that 95 parts by weight of HIZEX 5300B) were melt-mixed in an extruder and fed to a two-layer film die at a resin temperature of 230°C.

The adhesive strength of both layers was 4509/kil. Comparative example
2 The same procedure as in Example 2 was conducted except that high-density polyethylene without modified polyethylene was used.

Both layers of high-density polyethylene and polybutylene terephthalate did not adhere well. Example 3 High-density polyethylene (manufactured by Mitsui Petrochemical Co., Ltd., Izexx 1300J) grafted with 3% by weight of fumaric acid 5
A laminated film was obtained in the same manner as in Example 1 except that 96 parts by weight of low-density polyethylene (Milason M-50, manufactured by Mitsui Polychemicals) were used.

The adhesive strength of both layers was 580 y/me. Example
4 Same as Example 1 except that instead of the composition of 90 parts by weight of polybutylene terephthalate and 10 parts by weight of polyester copolymer in Example 1, a composition of 80 parts by weight of polybutylene terephthalate and 20 parts by weight of polyester copolymer was used. A laminated film was obtained in the same manner.

The adhesive strength between the polyolefin layer and the polybutylene terephthalate layer of this laminate was >1000 g/f. Example 5 A laminated film was obtained in the same manner as in Example 1, except that a composition containing 70 parts by weight of polybutylene terephthalate and 30 parts by weight of polyester copolymer was used.

The adhesive strength between the polyolefin layer and polybutylene terephthalate layer of this laminate is 520y/c? It was n. Example 6 Instead of the polyester copolymer used in Example 1, dimethyl terephthalate, ethylene glycol, and triethylene glycol were polycondensed, and the molar ratio of the glycol components ethylene glycol and triethylene glycol constituting the copolymer was The same procedure as in Example 1 was carried out except that a 90:10 polyester copolymer was used.

The interlayer adhesion strength of the obtained laminate was 360f1/CrrL
It was hot. Comparative Example 3 A laminated film was obtained in the same manner as in Example 1 except that the polybutylene terephthalate layer was made of only polybutylene terephthalate.

The interlayer adhesion strength of this film was 240k9/(V7!). Comparative Example 4 As a polyester copolymer, the dicarboxylic acid component consisted of 80 moles of terephthalic acid and 20 moles of adipic acid, and the glycol component consisted of ethylene glycol. A laminated film was obtained in the same manner as in Example 1 except that a polyester copolymer (intrinsic viscosity -0.56) was used.

Claims (1)

[Claims] 1. In manufacturing a laminate consisting of a polyolefin layer and a polybutylene terephthalate layer by melting a polyolefin and a polybutylene terephthalate and coextruding both resins from one die, the polyolefin layer is Part or all of the modified polyolefin is grafted with at least one monomer selected from unsaturated dicarboxylic acids or derivatives thereof, and the polybutylene terephthalate layer contains (a) 60 to 95 parts by weight of polybutylene terephthalate; and (b) a dicarboxylic acid component consisting of 90 mol% or more of terephthalic acid, and a general formula HC
(CH_2CH_2O)_nH (where n is an integer from 2 to 6) X mol% (12/n
)≦(X)≦(150/n)...(1) (where X in the formula is mol% of ether glycol in all glycols) and an alkylene glycol having 6 or less carbon atoms (100-X)
A method for producing a thermoplastic resin laminate, characterized in that the composition is a composition comprising 40 to 5 parts by weight of a polyester copolymer whose constituent component is a glycol component consisting of mol %. 2. The manufacturing method according to claim 1, wherein the polyolefin is low density polyethylene or ethylene-propylene copolymer. 3. The manufacturing method according to claim 1, wherein the unsaturated dicarboxylic acid or its derivative is maleic anhydride. 4. The manufacturing method according to claim 1, wherein the ether glycol is diethylene glycol or triethylene glycol. 5. The manufacturing method according to claim 1, wherein the alkylene glycol is ethylene glycol. 6 The mole %X of ether glycol in the glycol component of the polyester copolymer satisfies the following formula (24/n)≦(X)
The manufacturing method according to claim 1, wherein the manufacturing method is within a range satisfying ≦(120/n).