JPH0238611B2 - - Google Patents

Description

Claims 1 a at least one polyamide, and b oligomeric and polymers characterized by having (i) at least two unreacted phenolic hydroxy groups along the chain, capable of providing the improvements mentioned below. a sex phenol, and (ii)
The following formula: Dihydric and polyhydric phenols represented by [in the formula, n is 2 or 3, m is 3 or 4, and (n + m) = 6; p is 1 or 2, each r is independently 0, 1 or 2, Each s is independently 0, 1, 2, 3 or 4 as appropriate; t is 0, 1,
2, 3 or 4; each R is independently hydrogen;
Halogen; _C1 - _C16 alkyl, _C6 - _C18 aryl or _C7 - _C20 arylalkyl group (any of these can be substituted with a _C1 - _C12 alkyl group or a halogen atom, and an aryl group is present) or _{a hydroxyaryl} or _{alkylhydroxyaryl} group; and each R' each independently a carbon-carbon direct bond, or a divalent alkyl, aryl, arylalkyl, hydroxyaryl or alkylhydroxyaryl group (including halogen-substituted derivatives of each of these groups); divalent ester and amide groups; and -O-,

【formula】 【formula】

【formula】- S-,

【formula】

At least one phenolic additive selected from the group consisting of a member of the cross-linking group selected from the group consisting of hetero-containing cross-linking groups including There are no phenolic hydroxy groups with two adjacent alkyl groups on the phenolic ring with atoms),
A novel polyamide composition with reduced water absorption and improved swelling resistance when exposed to moisture. TECHNICAL FIELD This invention relates to novel polyamide compositions with low water absorption. More particularly, the present invention relates to polyamide compositions incorporating dihydric phenols that can reduce the sensitivity of the polyamide to water. BACKGROUND OF THE INVENTION Polyamides, also known as nylons, are well known and have enjoyed great commercial success. Although the majority of polyamides are used in the production of fibers and/or bristles, new and/or improved polyamides are increasingly used and in demand in applications that produce parts via molding processes, e.g. injection molding. There is.
Also, the development of blends of polyamides with rubber polymers and copolymers and other thermoplastics has greatly expanded the property distribution and thus the potential end uses for polyamides. However, despite advances in polyamide technology and development, its applications are still limited by polyamide's extreme sensitivity to moisture. Polyamide is directly immersed or exposed to water vapor itself,
For example, as a result of exposure to moisture due to high temperatures,
Tends to gain weight and swell or swell. As a result, polyamides and blends of polyamides still cannot be used in end applications where weight and, more importantly, dimensional stability are necessary and important. The present invention enables the production of polyamide compositions and polyamide blend compositions with significantly reduced water absorption. These compositions can therefore be used in end applications where maintaining part dimensional specifications is important. DISCLOSURE OF THE INVENTION The present invention provides a thermoplastic composition comprising at least one polyamide and at least one oligomeric or polymeric phenol and/or dihydric or polyhydric phenol in an amount sufficient to reduce the water absorption of the polyamide. It is a polyamide composition.
In particular, oligomeric and polymeric phenols such as polyvinylphenol and phenol formaldehyde resins, and the following formulas: It has been found that mixing dihydric and polyhydric phenols in amounts of from about 0.5 to about 30% by weight based on the polyamide significantly improves dimensional stability and reduces water absorption. where n is 2 or 3, m is 3 or 4, and (n+m)=6; p is 1 or 2,
Each r is independently 0, 1 or 2, each s is independently 0, 1, 2, 3 or 4 as appropriate; t is 0, 1, 2, 3 or 4, each R is independently hydrogen; halogen , such as bromine, chlorine, fluorine, etc.; _C1 - _C16 alkyl, _C6 - _C18 aryl or
_C7 - _C20 arylalkyl group (any of these
It can be substituted with a C ₁ -C ₁₂ alkyl group or a halogen atom, and when an aryl group is present, the aryl group can be substituted with -O-, C ₁ -C ₃ alkylene or alkylidene, or -SO ₂ - bridging group. or a hydroxyaryl or alkylhydroxyaryl group; and each
R′ is each independently a carbon-carbon direct bond, or a divalent alkyl, aryl, arylalkyl, hydroxyaryl, or alkylhydroxyaryl group (including halogen-substituted derivatives of each of these groups); a divalent ester and amide group; ; and -O-,

【formula】 【formula】

[Formula]-S --,

【formula】

It is selected from the group consisting of a member of the crosslinking group selected from the group consisting of hetero-containing crosslinking groups including [Formula] and the like. However, there is no phenolic hydroxy group having two adjacent alkyl groups on the phenol ring having a third carbon atom. DETAILED DESCRIPTION Polyamides suitable for use in the practice of this invention are well known and widely commercially available. Basically, polyamides are polymerized monoamino-monocarboxylic acids or lactams thereof having two or more carbon atoms between the amino and carboxylic acid groups;
Either a diamine containing two or more carbon atoms between amino groups and a dicarboxylic acid are polymerized in substantially equal molecular proportions; It can be obtained by polymerizing with dicarboxylic acid. Dicarboxylic acids are their functional derivatives,
For example, they can be used in the form of esters or acid chlorides. The term "substantially equimolecular" proportions (of diamine and dicarboxylic acid) refers to strictly equimolecular proportions and strictly equimolecular proportions indicated by conventional techniques to stabilize the viscosity of the resulting polyamide. It is used to cover both cases where there is a slight deviation from the above. The monoamino acids described above are useful in the production of polyamides.
Examples of monocarboxylic acids or their lactams include compounds containing 2 to 16 carbon atoms between the amino group and the carboxylic acid group; in the case of lactams, the carbon atoms form a ring with the -CO-NH group. is forming. Specific examples of aminocarboxylic acids and lactams include 6-aminocaproic acid, butyrolactam, pivalolactam, caprolactam, capryllactam, enantholactam, undecanolactam, dodecanolactam, and 3- and 4-aminobenzoic acids. can. Diamines suitable for use in making polyamides include alkyl, aryl and alkyl-aryl diamines. Examples of this type of diamine include those represented by the general formula: HF ₃ N(CHF ₃ )F ₃ NHF ₃ (n in the formula is an integer of 2 to 16), such as trimethylene diamine, tetramethylene diamine, pentamethylene These include diamines, octamethylene diamine, and especially hexamethylene diamine, as well as trimethylhexamethylene diamine, m-phenylene diamine, m-xylylene diamine, and the like. The dicarboxylic acids can be aromatic, such as isophthalic acid and terephthalic acid, or aliphatic. Among them, aliphatic dicarboxylic acids have the following formula: HOOC-Y-COOH, where Y represents a divalent aliphatic group containing two or more carbon atoms, examples of such acids include sebacin, acids, octadecanedioic acid, suberic acid, glutaric acid, pimelic acid and adipic acid. Typical examples of polyamides, ie nylons, include polypyrrolidone (nylon 4) polycaprolactam (nylon 6) polycapryllactam (nylon 8) polyhexamethylene adipamide
(Nylon 6,6) Polyundecanolactam (Nylon 11) Polydodecanolactam (Nylon 12) Polyhexamethylene azelainamide
(nylon 6,9) polyhexamethylene sebacamide
(nylon 6,10) polyhexamethylene isophthalimide
(Nylon 6, I) Polyhexamethylene terephthalamide
(Nylon 6,T) Polyamides of hexamethylene diamine and n-dodecanedioic acid (Nylon 6,12) and polyamides obtained from terephthalic acid and/or isophthalic acid and trimethylhexamethylene diamine, adipic acid and m-xylylene diamine polyamide, adipic acid, azelaic acid and 2,2-bis-(p-
There are polyamides obtained from (aminocyclohexyl)propane and polyamides obtained from terephthalic acid and 4,4'-diamino-dicyclohexylmethane. Copolymers of the above polyamides or prepolymers thereof are also suitable for use in practicing the present invention. This type of copolyamide includes the following copolymers: Hexamethylene adipamide/caprolactam
(Nylon 6,6/6) Hexamethylene adipamide/Hexamethylene isophthalamide (Nylon 6,6/6, I) Hexamethylene adipamide/Hexamethylene terephthalamide (Nylon 6,6/6, T) Hexamethylene Adipamide/hexamethylene azelainamide (nylon 6,6/6,9) hexamethylene adipamide/hexamethylene azelainamide/caprolactam
(Nylon 6, 6/6, 9/6) 2 of the above polyamides or their prepolymers
Mixtures and/or copolymers of more than one species, respectively, are also within the scope of the invention. The polyamides mentioned above are made more dimensionally stable and less sensitive to water absorption by the introduction of oligomeric or polymeric phenols or dihydric or polyhydric phenols. Oligomeric and polymeric phenols are
They are characterized by having free (ie, unreacted) phenolic hydroxy groups along the oligomer or polymer chain or by having pendant phenolic groups attached to the oligomer or polymer chain. These usually have a number average molecular weight of 40,000 or less, preferably about 400 to 30,000. Examples of suitable polymeric phenols include polyvinylphenols and phenol-formaldehyde resins (eg novolacs and resol resins). Suitable phenols are dihydric or polyhydric phenols, especially bisphenols. This type of phenol generally has the following formula: , where n is 2 or 3, m is 3 or 4, and (n+m)=6; p is 1 or 2, each r is independently 0, 1 or 2, and each s is independently appropriate 0, 1, 2, 3 or 4; t is 0, 1, 2, 3 or 4; each R is independently hydrogen; halogen, such as bromine, chlorine, fluorine, etc.; _C1 - _C16 alkyl, _C6 ~ _C18 aryl or
_C7 - _C20 arylalkyl group (any of these
It can be substituted with a C ₁ -C ₁₂ alkyl group or a halogen atom, and when an aryl group is present, the aryl group can be substituted with -O-, C ₁ -C ₃ alkylene or alkylidene, or -SO ₂ - bridging group. or a hydroxyaryl or alkylhydroxyaryl group; and each
R′ is each independently a carbon-carbon direct bond, or a divalent alkyl, aryl, arylalkyl, hydroxyaryl, or alkylhydroxyaryl group (including halogen-substituted derivatives of each of these groups); a divalent ester and amide group; ; and -O-,

【formula】 【formula】

[Formula]-S --,

【formula】

A member of the group consisting of a hetero-containing bridging group selected from the group consisting of a hetero-containing bridging group including [Formula], etc., provided that it has two adjacent alkyl groups on the phenol ring having a tertiary α carbon atom. There are no phenolic hydroxy groups present. Examples of phenols corresponding to the above formula are:
Resorcinol, hydroquinone, 1,2,4-benzenetriol, phloroglucinol, 2,2
-Bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, 2,2-
Bis(4-hydroxyphenyl)heptane, 2,
2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-
Bis(3,5-dibromo-4-hydroxyphenyl)propane, 4,4'-(p-phenylenediisopropylidene)-bis-(2,6-xylenol), 4,4'-(p-phenylenediisopropylidene)-bis-(2,6-xylenol), nylene diisopropylidene) bisphenol, methylene bisphenol, biphenol, naphthalene diol, 4,
4′-cyclohexylidene bisphenol, α,
α′,α″-bis(4-hydroxyphenol)-
1,3,5-triisopropylbenzene, 2,2
-Bis(3-methyl-4-hydroxyphenyl)
Propane, 2,2-bis(3,5-dimethyl-4
-Hydroxyphenyl)sulfone, 2,2-
(2,4-dihydroxyphenyl)sulfone, etc. The amount of polymeric phenol or bisphenol used in the practice of this invention is such that it imparts dimensional stability to the polyamide and reduces its water absorption, preferably by at least 10% compared to the unmodified polyamide. This is the amount of improvement that can be obtained. Generally, the amount of phenol is from about 0.5 to about 30, preferably from about 2 to about 25 weight percent, based on the combined weight of phenol and polyamide. The present invention can also be applied to polyamide compositions containing a second thermoplastic polymer and/or a rubbery impact modifier. The weight ratio of the second thermoplastic polymer to the polyamide can be practically used in essentially any weight ratio, such as 1-99:99-1, depending on the desired properties of the final blend composition. However, blends containing rubbery impact modifiers should contain no more than 50% by weight, preferably from about 5 to about 35% by weight, based on the total composition. Suitable thermoplastic polymers that can be included in the blends contemplated by this invention include polyimides, polyamideimides, polyetherimides, polyalkylene ethers, polyphenylene ethers, polyarylates, polyesteramides, polyesters, etc. There is. All of these thermoplastic polymers are well known and widely commercially available. Suitable rubbery impact modifiers are also well known and widely commercially available. Examples of the many rubbery impact modifiers included within the scope of this invention include polyolefins and copolyolefins, such as polyethylene, polypropylene, ethylene-propylene copolymers, copolymers of ethylene with acrylic acids and alkyl acrylic acids. Coalescence, etc. Ethylene-propylene-
Diene monomer rubber (EPDM); diene rubber and copolymers such as polybutadiene, polyisoprene, styrene-butadiene copolymer, styrene-butadiene-styrene block copolymer, etc.;
Mention may be made of nitrile rubbers and copolymers, such as styrene-acrylonitrile, acrylonitrile-butadiene-styrene type copolymers, and the like. Suitable rubbery impact modifiers of this type include:
US Pat. No. 2,933,480, US Pat. No. 2,962,451, and US Pat.
No. 3000866, No. 3093620, No. 3093621, No.
No. 3063973, No. 3147230, No. 3154528, No.
No. 3260708, and Sittig, “Stereo Rubber and Other Elastic Methods”
Rubber and Other Elastic Process), Noyes Development Company (Noyes
Development Corporation), Park Ridge, NJ, USA, 1967
, all of which are incorporated by reference into the present invention. A preferred group of rubbery impact modifiers include those described above that interact chemically (e.g., bonding) or physically with the polyamide to increase its impact strength over non-functionalized rubbers. (unreacted) pendant functional groups that can be further increased, such as carbonyl, carboxy, carboxylic acid anhydride,
Monomers containing epoxies, ethers, esters, amines, amides, etc. are copolymerized or grafted. Functionalized rubbery impact modifiers of this type and their blends with polyamides are commercially available, inter alia U.S. Pat. No. 4,174,358;
No. 4474927, No. 4346194, No. 4251644, No.
No. 3884882, No. 4147740, No. 3388186, and No. 3465059, and “Preparation and Reactions of Epoxy-Modified Polyethylene” by Gallucci et al.
27, pp. 425-437 (1982), all of which are cited as references for the present invention. If desired, the compositions of the invention can also contain one or more fillers and/or reinforcing agents. Examples of such fillers and/or reinforcements are glass fibers, carbon fibers, glass spheres, inorganic fillers such as mica and silica, carbon black, etc. If such fillers and/or reinforcements are used, no more than about 50% by weight of the composition, based on the total composition, preferably from about 5 to about
It should contain 30% by weight. Finally, the compositions of the invention may also contain other ingredients such as flame retardants, colorants, nucleating agents, anti-drip agents, stabilizers, etc., in effective amounts known in the art according to the purpose for which they are customarily used. can do. The compositions of the present invention can be made by any known melt blending method. For example, the ingredients can be dry blended, extruded or milled into a powder, or manufactured by extrusion compounding. Apparatus suitable for this type of process include extruders, Banbury mixers, rollers, kneaders, etc. These compositions can also be manufactured by continuous or batch processing. The following examples are provided to enable those skilled in the art to better understand how to carry out the invention. These examples are given for illustrative purposes only, and the invention is not limited thereto. All compositions are given in parts by weight unless otherwise specified. All blends were made by extrusion at 250-300°C in a single-screw or twin-screw extruder. All ingredients were mixed and fed together. After drying, the blend composition was injection molded to produce test parts. Water uptake and swelling were typically measured on samples soaked in deionized water at 75°C for approximately 40 hours. Samples were cooled to room temperature for testing. In some cases, water uptake was measured on samples that had been soaked in water for three weeks at room temperature. The two methods gave similar results. Examples 1-7, Comparative Examples A-F A series of polyamides and polyamide blend compositions were prepared to demonstrate the applicability of the present invention to various polyamide compositions. In these examples, the bisphenol used was 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). The compositions of the specific examples and the results obtained for each example were as shown in Table 1. As can be seen from the examples in Table 1, bisphenol A increases water absorption, both in polyamide alone and in its blends with other thermoplastic polymers.
And more importantly, moisture swelling was significantly reduced. It was also observed that the addition of bisphenol A increased the processability of the composition, resulting in increased spiral flow.

【table】

TABLE Examples 8-10, Comparative Example G A second series of blends was prepared to demonstrate the effectiveness of bisphenols at various loading levels. The specific composition of each blend and the results obtained are as shown in Table 2.

[Table] Examples 11 to 16, Comparative Example H In order to demonstrate the water absorption reduction effects of various bisphenol polyamide compositions, a series of compositions were manufactured. The specific composition and physical properties of each composition were as shown in Table 3. Each composition in Table 3 consists of 45 parts polyphenylene ether, 45 parts polyamide 6,6; 10 parts styrene-hydrogenated butadiene-styrene triblock copolymer;
Contains 100% of citric acid hydrate and the bisphenols shown in the table. Weight gain rate at room temperature
Samples immersed in water for 21 days were tested.

【table】

Table: Examples 17-18, Comparative Examples A final series of compositions were prepared to demonstrate the effectiveness of the polymeric phenols used in the practice of this invention. These compositions and their physical properties were as shown in Table 4. All compositions included 45 parts polyphenylene oxide, 45 parts polyamide 6,6, 10 parts styrene-hydrogenated butadiene-styrene triblock copolymer, and
Contains 0.35 parts of maleic anhydride. Swelling and weight gain were measured on samples soaked in water for 40 hours at 75°C. The improvement rate is shown in the box.

[Table] Lufenol A ^a

[Table] Of course, further modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that modifications may be made to the specific embodiments of the invention described above within the full scope defined by the appended claims.