U.S. patent application number 11/489111 was filed with the patent office on 2006-11-16 for polyamide molding compositions.
Invention is credited to Detlev Joachimi, Ralph Ulrich.
Application Number | 20060258807 11/489111 |
Document ID | / |
Family ID | 33441447 |
Filed Date | 2006-11-16 |
United States Patent
Application |
20060258807 |
Kind Code |
A1 |
Ulrich; Ralph ; et
al. |
November 16, 2006 |
Polyamide molding compositions
Abstract
A thermoplastic molding composition comprising polyamide is
disclosed. The composition that contains vinyl (co)polymer and an
optional solvent is useful in application where inhibited
crystallization of polyamide is desirable, including
laser-welding.
Inventors: |
Ulrich; Ralph; (Ratingen,
DE) ; Joachimi; Detlev; (Krefeld, DE) |
Correspondence
Address: |
LANXESS CORPORATION
111 RIDC PARK WEST DRIVE
PITTSBURGH
PA
15275-1112
US
|
Family ID: |
33441447 |
Appl. No.: |
11/489111 |
Filed: |
July 19, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10850912 |
May 21, 2004 |
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11489111 |
Jul 19, 2006 |
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Current U.S.
Class: |
525/178 |
Current CPC
Class: |
B29C 48/08 20190201;
B29K 2101/12 20130101; C08L 77/02 20130101; B29C 66/71 20130101;
B29C 66/73774 20130101; C08L 77/06 20130101; B29C 51/00 20130101;
B29K 2077/00 20130101; B29C 66/71 20130101; B29C 49/00 20130101;
B29C 65/1674 20130101; B29C 65/1616 20130101; B29K 2995/0039
20130101; B29C 66/7212 20130101; B29C 66/7212 20130101; C08L 39/06
20130101; B29K 2995/0027 20130101; B29C 65/1635 20130101; B29C
48/022 20190201; C08L 77/02 20130101; C08L 77/00 20130101; C08L
77/00 20130101; B29C 66/73365 20130101; C08L 77/06 20130101; C08L
2666/04 20130101; C08L 2666/04 20130101; B29K 2077/00 20130101;
C08L 2666/04 20130101; B29K 2309/08 20130101; C08L 39/04 20130101;
B29C 66/73921 20130101 |
Class at
Publication: |
525/178 |
International
Class: |
C08L 77/00 20060101
C08L077/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2003 |
DE |
10324324.0 |
Claims
1. A method of laser-welding, comprising: producing a molding
composition comprising, A) 90-99.995 wt % polyamide, B) 0.005-5 wt
% vinyl (co)polymer, and C) 0-5 wt % solvent; wherein the wt % are
relative to the total weight of the composition; providing at least
a first joining partner and a second joining partner having a
contact zone there between, wherein at least one joining partner is
made of the molding composition; applying radiation from a
transmission laser to the contact zone; and forming a weld bond
between at least the first joining partner and the second joining
partner to form an article.
2. The method of claim 1, wherein A) is present in an amount of
95-99.994 wt %, B) is present in an amount of 0.005-1 wt % and C)
is present in an amount of 0.001-1 wt %.
3. The method of claim 1, wherein A) is present in an amount of
99-99.965 wt %, B) is present in an amount of 0.005-0.8 wt % and C)
is present in an amount of 0.03-0.4 wt %.
4. The method of claim 1, wherein the molding composition further
comprises at least one member selected from the group consisting of
fillers, reinforcing fillers, conventional additives, colorants and
combinations thereof.
5. The method of claim 1, wherein component B) is selected from the
group consisting of poly-N-vinyllactam, poly-N-vinylpyrrolidone
copolymers of vinyllactam, copolymers of vinylpyrrolidone, and
combinations thereof.
6. The method of claim 1, wherein the polyamide of A) is selected
from the groups consisting of polyamide 6, polyamide 66, polyamide
11, polyamide 12, polyamide 610, polyamide 6I, polyamide 612,
polyamide 6/66, polyamide 6I/6T, polyamide MXD6, polyamide 6/61,
polyamide 6/6T, polyamide 6/IPDI and copolymers of these polyamides
and combinations of these polyamides.
7. The method of claim 1, wherein the polyamide of A) is polyamide
66.
8. The method of claim 1, wherein the solvent is selected from the
group consisting of water, alcohol, ketone, glacial acetic acid,
chlorinated hydrocarbon, phenol and combinations thereof.
9. The method of claim 1, wherein the radiation emitted by the
laser is at a wavelength of 800-1060 nm.
10. The method of claim 1, wherein the first joining partner
comprises the molding composition.
11. The method of claim 1, wherein the article is hollow.
12. The method of claim 1, wherein the article is of multi-layer
construction.
13. The method of claim 1, wherein the molding composition is
produced by a continuous process.
14. The method of claim 13, wherein components B) and C) are added
as a homogenous solution directly onto granules of the polyamide of
component A).
15. The method of claim 13, wherein components B) and C) are added
as a solid to the polyamide of component A) during compounding.
16. The method of claim 13, wherein components B) and C) are added
as a liquid to the polyamide of component A) during
compounding.
17. The method of claim 1, wherein the molding composition is
produced by a discontinuous process.
18. The method of claim 1, wherein component B) is added directly
to the polyamide of component A) prior to welding.
19. The method of claim 1, wherein component B) is homogenously
distributed throughout the molding composition.
20. The method of claim 1, wherein the molding composition
comprises less than 500 ppm of component B).
Description
CROSS REFERENCE
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/850,912 filed May 21, 2004 entitled "Polyamide Molding
Compositions", the contents of which are hereby incorporated by
reference in their entirety.
FILED OF THE INVENTION
[0002] The present invention relates to thermoplastic molding
compositions and more particularly to polyamide molding
compositions.
SUMMARY OF THE INVENTION
[0003] A thermoplastic molding composition comprising polyamide is
disclosed. The composition that contains vinyl (co)polymer and an
optional solvent is useful in the application where inhibited
crystallization of polyamide is desirable, including
laser-welding.
BACKGROUND OF THE INVENTION
[0004] Polyamides are distinguished by a large number of
advantageous properties, such as e.g. high toughness, high
temperature resistance etc., which guarantee them a secure market
position in the engineering thermoplastics sector. These basic
properties of the polymer are generally modified by the addition of
fillers or additives. Polymer and additives together form the
so-called molding composition. Polyamide molding compositions are
used in many applications. Injection molded parts, e.g. for the
automotive market, or extrudates such as films or hollow articles
for the packaging sector may be mentioned as examples.
[0005] Films and hollow articles containing a polyamide layer are
distinguished by a large number of advantageous properties.
Particularly worthy of mention are good optical properties, such as
high transparency of films or hollow articles with high surface
gloss. Also significant are the good mechanical properties, such as
high toughness, high puncture resistance, high tear propagation
resistance and others. Ease of production and ease of further
processing are added to these.
[0006] Of particular significance for many areas of application for
films and molding compositions, particularly for use in the
packaging sector, e.g. for foodstuffs or cosmetics, is control of
the rate of crystallization of the material used, to provide a
specific influence on properties such as e.g. shrinkage or impact
strength.
[0007] In the area of the use of polyamide in the production of
films, a fundamental distinction must be drawn between the flat
film production process and the blown film production process.
[0008] Particularly in the area of application in the blown film
sector, polyamides with slower crystallization than conventional
polyamide 6 are necessary to enable the primary tube to be blown
and stretched in the blown film production process before the film
has reached too high a degree of crystallization.
[0009] At present, this goal is achieved by the use of
copolyamides. The most widespread copolyamide in blown film
extrusion is a copolyamide consisting of polyamide 6 and polyamide
66, which usually contains between 15 wt. % and 20 wt. % polyamide
66.
[0010] However, other copolyamides with delayed crystallization are
also described (e.g. EP-A 561 226). Here, copolyamides of
caprolactam, isophthalic acid and hexamethylene diamine with
reduced crystallinity compared with conventional polyamides are
described. Increased transparency of the multi-layer film claimed
is achieved by the reduced crystallinity after processing.
[0011] These copolyamides are conventionally produced not by the
continuous tubular reactor process, which is widespread for
polyamide 6, but by special processes, as described in EP-A 98 412,
EP-A 393 546 or WO-A 9421711.
[0012] It is known that the transparency of polyamides may be
improved by incorporating poly-N-vinylpyrrolidones at the
polymerization or compounding stage (DE-A 1 595 613).
[0013] The Japanese patent application JP-A 2002306059 describes
the coextrusion of a blend of 96% polyamide 6-polyamide 66
copolymer with 4% of a crosslinked N-vinylpyrrolidone to produce
packaging for foodstuffs having moderate water vapor permeability
and a good oxygen barrier.
[0014] The use of poly-N-vinyllactam or poly-N-vinylpyrrolidones is
also widespread in the fiber production sector. Here, for example,
to increase the hydrophilic properties, 3 wt. % to 15 wt. % of the
above compounds are incorporated by compounding. A high proportion
of poly-N-vinyllactam or poly-N-vinylpyrrolidone has a negative
effect on the yellowness index, however (EP 802 268).
[0015] In the area of compounded products, nigrosine base is
conventionally used to slow down crystallization, but this leads to
a black discoloration of the product.
[0016] For applications such as the laser transmission welding of
polyamide moldings, materials with the lowest possible
crystallinity are needed, since the transmission of laser light
decreases with increasing crystallinity. Basic principles of laser
transmission welding are described in the specialist literature
(Kunststoffe 87 (1997) 3, 348-350; Kunststoffe 88 (1998) 2,210-212;
Kunststoffe 87 (1997) 11, 1632-1640; Plastverarbeiter 50 (1999) 4,
18-19; Plastverarbeiter 46 (1995) 9, 42-46).
[0017] A prerequisite for the use of laser beam welding is that the
radiation emitted by the laser first passes through a joining
partner, which is sufficiently transparent for laser light of the
wavelength used, and is then absorbed by the second joining partner
in a thin layer of a few 100 .mu.m and converted to heat, which
leads to melting in the contact zone and finally to the bonding of
the two joining partners by a weld.
[0018] While it is true that, in the wavelength range of the lasers
conventionally used for thermoplastic welding (Nd:YAG laser:1060
nm; high-performance diode laser:800- 1000 nm), partially
crystalline thermoplastics such as polyamides, e.g. polyamide 6
(PA6) and polyamide 66 (PA66) are transparent or laser-translucent,
the transmission is often inadequate for good weldability, and so
modifications are required for higher transmission.
[0019] The nigrosine base does indeed reduce crystallinity, but in
the frequency range of 800-1100 nm which is of interest for laser
transmission welding, it has marked self-absorptions.
[0020] The object of the present invention consequently is to
develop a polyamide, preferably polyamide 6, composition in which
crystallization is inhibited that is characterized by the absence
of any undesirable discoloration.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Surprisingly, it has now been found that, by adding vinyl
homopolymers and/or copolymers of vinyl monomers and preferably a
solvent to the polyamide, it has been possible to achieve this
object.
[0022] Crystallisation inhibition can be achieved preferably with
poly-N-vinyllactam and poly-N-vinylpyrrolidone, as well as
copolymers consisting of vinyllactam, and/or vinylpyrrolidone and
other vinyl monomers, such as e.g. vinyl acetate and/or
vinylimidazole and/or quaternized vinylimidazole and/or vinyl
acrylate and/or methacrylates, such as e.g. methyl methacrylate,
sodium methacrylate or cyclohexyl methacrylate and/or acrylamide
and/or acrylonitrile and/or N-vinylcarbazole and/or styrenes, such
as e.g. p-aminostyrene, with good distribution in the polymer
matrix. For this homogenisation, a solvent for the homopolymers or
copolymers can be advantageous according to the invention.
[0023] The invention therefore provides compositions containing A)
polyamide and B) vinyl homopolymers and/or copolymers of vinyl
monomers and preferably a solvent.
[0024] Preferred B) vinyl homopolymers and/or copolymers of vinyl
monomers are poly-N-vinyllactam and poly-N-vinylpyrrolidone, as
well as copolymers consisting of vinyllactam, and/or
vinylpyrrolidone and other vinyl monomers, such as e.g. vinyl
acetate and/or vinylimidazole and/or quaternised vinylimidazole
and/or vinyl acrylate and/or methacrylates, such as e.g. methyl
methacrylate, sodium methacrylate or cyclohexyl methacrylate and/or
acrylamide and/or acrylonitrile and/or N-vinylcarbazole and/or
styrenes, such as e.g. p-aminostyrene.
[0025] Preferred amount of B is 0.005-5 wt. %, particularly
preferably 0.005-1 wt. % and especially preferably 50-8000 ppm
based on the weight of the composition.
[0026] As the solvent C, water, alcohols, such as e.g. polyethylene
glycols, ketones, glacial acetic acid, chlorinated hydrocarbons and
phenols are preferred.
[0027] Particularly preferred are polyethylene glycols with a
molecular weight of between 100 g/mol and 2,000 g/mol, and
especially preferred are polyethylene glycols with an average
molecular weight of between 200 g/mol and 600 g/mol.
[0028] Solvent C: preferred amounts are 0.001-5 wt. %, particularly
preferably 0.001-1 wt. % and especially preferably 300-4000 ppm,
based on the weight of the composition.
[0029] In the case of concentrations of B of less than 5,000 ppm, a
C) solvent for poly-N-vinyllactam or poly-N-vinylpyrrolidone is
preferred in which the poly-N-vinyllactam or poly-N-vinylrrolidone
is applied directly on to the granules in solution.
[0030] In addition, in the case of molding compositions for
processing by injection molding or extrusion (profiles,
blow-moldings), the molding compositions may contain conventional
additives and colorants.
[0031] The invention also provides the use of the inventive
compositions for the production of polyamide molding compositions
and their use for the production of films, hollow articles,
injection moldings and extruded profiles.
[0032] The invention also provides preferably single-layer or
multi-layer films or hollow articles containing at least one layer
of the inventive molding composition.
[0033] The invention additionally provides packaging containing a
film or a hollow article comprising the inventive composition.
[0034] The invention additionally provides moldings bonded together
by laser transmission welding in which at least the part facing the
laser source comprises the inventive composition.
[0035] Preferred, particularly preferred or especially preferred
are embodiments that make use of the parameters, compounds,
definitions and explanations mentioned as preferred, particularly
preferred or especially preferred.
[0036] However, the definitions, parameters, compounds and
explanations listed above, either general or listed in preferred
areas, may also be combined with one another, i.e. between the
respective areas and preferred areas.
[0037] The polyamide contained in the polyamide layer of the
molding compositions, films or hollow articles according to the
invention is a known, aliphatic or aromatic or partially aromatic
homopolyamide or copolyamide or a mixture of several polyamides.
For example, and independently of one another, PA6, PA66, PA 11,
PA12, PA 46, PA610, polyamide 6, polyamide 10, polyamide 12,
polyamide 66, polyamide 610, polyamide 6I, polyamide 612, polyamide
6/66, polyamide 6I/6T, polyamide MXD6, polyamide 6/6I, polyamide
6/6T, polyamide 6/IPDI and copolymers, as well as polymer mixtures
of these groups, are preferably used.
[0038] PA 6 or PA 66 or a copolyamide of caprolactam units and
units derived from hexamethylenediamine and isophthalic acid or
hexamethylenediamine and terephthalic acid or hexamethylenediamine
and adipic acid is particularly preferably used. These units
derived from hexamethylenediamine and isophthalic acid or
hexamethylenediamine and terephthalic acid or hexamethylenediamine
and adipic acid are called copolyamide proportions. Copolyamide
proportions of 0-50 wt. % are preferred, copolyamide proportions of
between 0 and 25 wt. % are particularly preferred and 0-15 wt. %,
based on A, are especially preferred.
[0039] The modification of the polyamides according to the
invention preferably takes place with poly-N-vinyllactam and
poly-N-vinylpyrrolidones having weight average molecular weights of
20,000 g/mol to 2,000,000 g/mol; polyvinylpyrrolidones having
molecular weights of between 50,000 g/mol and 1,500,000 g/mol are
particularly preferred and polyvinylpyrrolidones having molecular
weights of approx. 1,300,000 g/mol are especially preferred.
[0040] The films or hollow articles according to the invention may
include one polyamide layer or have a multi-layer construction. In
the case of the multi-layer construction, the other layers may
include e.g. polyolefins, such as e.g. polyethylene or polyethylene
copolymers, such as e.g. copolymers of ethylene and acrylic acid or
methacrylic acid or barrier polymers, such as e.g. polyvinylidene
chloride or copolymers of ethylene and vinyl alcohol or of other
polyamide layers.
[0041] The molding compositions, films, hollow articles, profiles
or injection moldings according to the invention are produced by
known means, e.g. by extrusion, coextrusion, coating, laminating,
blow molding or injection molding processes. In the case of films,
the extrusion or coextrusion may take place e.g. by the so-called
chill roll process or by the extrusion blow molding process or
coextrusion blow molding process. In the case of multi-layer films
or hollow articles, commercially available coupling agents may be
used.
[0042] The starting polyamides for the polyamide molding
compositions according to the invention may be produced by known
means in a continuous or discontinuous process. A discontinuous
process may be e.g. polymerization in an autoclave. A continuous
process may be e.g. polymerization in a continuous tubular reactor.
The production preferably takes place by a continuous process. To
achieve high molecular weights, as are often needed for use as a
film material, polymerization in the melt can be followed by a
post-condensation in the solid phase. The addition of the
poly-N-vinyllactam or poly-N-vinylpyrrolidones takes place in the
form of a homogeneous solution after the last viscosity-building
process step directly on to the granules.
[0043] Alternatively, addition as a solid or liquid or solution
during compounding, e.g. in a twin-screw extruder or kneader, is
also possible during the production of compounds. As a further
alternative, the addition of the poly-N-vinyllactam or
poly-N-vinylpyrrolidones is possible in pure form or as a
homogeneous solution, directly before processing suitable compounds
on an injection-molding machine.
[0044] The molding compositions, films, hollow articles, profiles
or injection moldings according to the invention can be further
processed or formed before their ultimate end use. Thus, for
example, the films according to the invention may be thermo-formed.
The films or hollow articles according to the invention may be used
e.g. for packaging purposes. Films or hollow articles according to
the invention may, for example, be employed for packaging
foodstuffs, such as meat and meat products, sausage, cheese, drinks
etc. The films or hollow articles according to the invention may
also, for example, be employed for packaging cosmetics, such as
e.g. sun protection creams, or chemicals, such as e.g. plant
protection agents. In addition, the hollow articles according to
the invention may be used as pipes or tanks. These can be e.g.
pipes or tanks for fuels or oils for cars.
[0045] Laser transmission welded injection moldings may be used
e.g. as housings for electrical components and/or sensors.
[0046] The clear inhibition of crystallisation found here is
achieved by the addition of poly-N-vinyllactam or
poly-N-vinylpyrrolidone or copolymers consisting of vinyllactam,
and/or vinylpyrrolidone as well as other vinyl monomers, such as
e.g. vinyl acetate and/or vinylimidazole and/or quaternised
vinylimidazole and/or vinyl acrylate and/or methacrylates, such as
e.g. methyl methacrylate, sodium methacrylate or cyclohexyl
methacrylate and/or acrylamide and/or acrylonitrile and/or
N-vinylcarbazole and/or styrenes, such as e.g. p-aminostyrene or a
homogeneous solution of poly-N-vinyllactam or
poly-N-vinylpyrrolidone, or copolymers consisting of vinyllactam
and/or vinylpyrrolidone as well as other vinyl monomers, such as
e.g. vinyl acetate and/or vinylimidazole and/or quaternised
vinylimidazole and/or vinyl acrylate and/or methacrylates, such as
e.g. methyl methacrylate, sodium methacrylate or cyclohexyl
methacrylate and/or acrylamide and/or acrylonitrile and/or
N-vinylcarbazole and/or styrenes, such as e.g. p-aminostyrene.
[0047] Surprisingly, the action of the solution of
poly-N-vinyllactam or poly-N-vinyl-pyrrolidones according to the
invention occurs with additions of as little as <500 ppm. Only
the homogeneous distribution makes extrusion into films possible,
since only in this way may increased fish eye formation be
avoided.
[0048] In the case of a special application, the polyamides
according to the invention may be adapted to form materials with
specially adjusted combinations of properties, alone or in
combination with processing auxiliary substances, stabilisers,
polymeric alloying materials (e.g. elastomers) or also reinforcing
materials (such as e.g. mineral fillers or glass fibers). Blends
with proportions of other polymers, e.g. of polyethylene,
polypropylene or ABS, are also suitable. The properties of the
polyamides may be improved by adding elastomers, e.g. in terms of
the impact strength of e.g. reinforced polyamides. The many
possible combinations enable a very large number of products to be
obtained with widely varying properties.
[0049] The polyamides produced according to the invention may also
be used in a mixture with other polyamides and/or other
polymers.
[0050] In addition, the polyamide molding compositions may also
contain flame retardants, such as e.g. phosphorus compounds,
organic halogen compounds, nitrogen compounds and/or magnesium
hydroxide, stabilizers, processing auxiliary substances, such as
e.g. lubricants, nucleating agents, stabilizers, impact modifiers,
such as e.g. rubbers or polyolefins and the like.
[0051] In addition to glass fibers, aramid fibers, mineral fibers
and whiskers are suitable as fibrous reinforcing fillers. Calcium
carbonate, dolomite, calcium sulfate, mica, fluoromica,
wollastonite, talcum and kaolin may be mentioned as suitable
mineral fillers. To improve the mechanical properties, the fibrous
reinforcing fillers and the mineral fillers may be
surface-treated.
[0052] The addition of the fillers may take place before, during or
after the polymerisation of the monomers to form the polyamide. If
the addition of the fillers according to the invention takes place
after the polymerization, it preferably takes place by addition to
the polyamide melt in an extruder. If the addition of the fillers
according to the invention takes place before or during the
polymerisation, the polymerization can comprise phases in which
work is carried out in the presence of 1 to 50 wt. % water.
[0053] When they are added, the fillers may already be present as
particles with the particle size ultimately occurring in the
molding composition. Alternatively, the fillers may be added in the
form of precursors, from which the particles ultimately occurring
in the molding composition are formed only during the course of the
addition or incorporation.
[0054] Suitable as fire or flame retardants are, for example, red
phosphorus (DE-A-3 713 746 A 1 (=US-A-4,877,823) and EP-A-299 444
(=US-A-5,081,222), brominated diphenyls or diphenyl ethers in
combination with antimony trioxide and chlorinated cycloaliphatic
hydrocarbons (Dechlorane.RTM. plus from Occidental Chemical Co.),
brominated styrene oligomers (e.g. in DE-A-2 703 419) and
polystyrenes brominated in the nucleus (e.g. Pyro-Check 68.RTM.
from FERRO Chemicals).
[0055] As a synergist to the above-mentioned halogen compounds, for
example zinc compounds or iron oxides are used.
[0056] As another alternative, melamine salts in particular have
proved a suitable flame retardant particularly for unreinforced
polyamides.
[0057] In addition, magnesium hydroxide has long proved a suitable
flame retardant for polyamide.
[0058] In addition to glass fibers, the polyamide molding
compositions may additionally contain rubber-elastic polymers
(often also referred to as an impact modifier, elastomer or
rubber).
[0059] Sterically hindered phenols and/or phosphites,
hydroquinones, aromatic secondary amines, such as diphenylamines,
various substituted representatives of these groups and mixtures
thereof in concentrations of up to 1 wt. %, based on the weight of
the thermoplastic molding compositions, are mentioned as examples
of antioxidants and heat stabilisers.
[0060] Various substituted resorcinols, salicylates, benzotriazoles
and benzophenones may be mentioned as UV stabilizers, which are
generally used in quantities of up to 2 wt. %, based on the molding
composition.
[0061] Sodium phenyl phosphinate, aluminium oxide, silicon dioxide
and preferably talcum, for example, may be used as nucleating
agents.
[0062] Lubricants and mold release agents, which are conventionally
used in quantities of up to 1 wt. %, are preferably ester waxes,
pentaerythritol stearate (PETS), long-chain fatty acids (e.g.
stearic acid or behenic acid), the salts thereof (e.g. Ca or Zn
stearate) and amide derivatives thereof (e.g.
ethylenebisstearamide) or montan waxes, as well as low molecular
weight polyethylene or polypropylene waxes.
[0063] Dioctyl phthalate, dibenzyl phthalate, butyl benzyl
phthalate, hydrocarbon oils and N-(n-butyl)benzenesulfonamide may
be mentioned as examples of plasticizers.
[0064] Particularly preferred is the additional use of
rubber-elastic polymers (often also referred to as impact modifier,
elastomer or rubber).
[0065] In general these are copolymers, which are preferably
constructed from at least two of the following monomers: ethylene,
propylene, butadiene, isobutene, isoprene, chloroprene, vinyl
acetate, styrene, acrylonitrile and acrylates or methacrylates with
1 to 18 C atoms in the alcohol component.
[0066] These polymers are described e.g. in Houben-Weyl, Methoden
der organischen Chemie, vol. 14/1 (Georg-Thieme Verlag, Stuttgart,
1961), pages 392 to 406 and in the monograph by C. B. Bucknall,
"Toughened Plastics" (Applied Science Publishers, London,
1977).
[0067] Mixtures of rubber types may, of course, also be used.
[0068] Suitable as colorants are both organic and inorganic
pigments and/or dyes. Carbon black is optionally a component of the
pigment mix in very small quantities. The pigments/dyes and/or
carbon blacks may optionally also be used as a batch.
[0069] Examples of inorganic pigments are antimony trioxide,
antimony pentoxide, basic lead carbonate, basic lead sulfate or
lead silicate, lithopones, titanium dioxide (anatase, rutile), zinc
oxide, zinc sulfide, metal oxides such as Berlin blue, lead
chromate, lead sulfochromates, chromium antimony titanate, chromium
oxides, iron oxides, cobalt blue, cobalt-chromium blue,
cobalt-nickel grey, manganese blue, manganese violet, molybdenum
orange, molybdenum red, nickel-antimony titanate, ultramarine blue,
as well as metal sulfides such as antimony trisulfide, cadmium
sulfide, cadmium sulfoselenides, zirconium silicates,
zirconium-vanadium blue and zirconium-praseodymium yellow.
[0070] Examples of organic pigments are anthraquinone, azo,
azomethine, benzanthrone, quinacridone, quinophthalone, dioxazine,
flavanthrone, indanthrone, isoindoline, isoindolinone, methine,
perinone, perylene, phthalocyanine, pyranthrone, pyrrolopyrrole and
thioindigo pigments as well as metal complexes of e.g. azo,
azomethine or methine dyes or metal salts of azo compounds.
[0071] Suitable as polymer-soluble dyes are, for example,
dispersion dyes, such as those of the anthraquinone series, e.g.
alkylamino, amino, arylamino, cyclohexylamino, hydroxy,
hydroxyamino or phenylmercaptoanthraquinones, as well as metal
complexes of azo dyes, particularly 1:2 chromium or cobalt
complexes of monoazo dyes, as well as fluorescent dyes, e.g. those
of the benzothiazole, coumarin, oxarine or thiazine series.
[0072] The polymer-soluble dyes may also be used in combinations
with fillers and/or pigments, particularly with inorganic pigments
such as titanium dioxide.
[0073] Pigments and/or polymer-soluble dyes may be used. In the
case of dyeing molding compositions that have to be
laser-translucent, the dyes or pigments used may, of course, have
no or only very low absorption in the NIR spectral range and should
be compatible with the thermoplastic polymers used according to the
invention and not substantially impair their mechanical or other
properties.
[0074] Suitable pigment additives are e.g. fatty acids with at
least 12 C atoms, such as behenic acid or stearic acid, their
amides, salts or esters, such as aluminium stearate, magnesium
stearate, zinc stearate or magnesium behenate, as well as
quaternary ammonium compounds, such as
tri(C.sub.1-C.sub.4)-alkylbenzylammonium salts, waxes, such as
polyethylene wax, resin acids, such as abietic acid, colophony
soap, hydrogenated or dimerised colophony, C.sub.12-C.sub.18
paraffin disulfonic acids or alkylphenols.
[0075] Preferred are dyes of the pyrazolone, perinone and
anthraquinone type, and of the methine, azo and coumarin type.
[0076] Also preferred are the metal-containing pigments, such as
the inorganic pigments and the metal complexes of azo, azomethine
or methine dyes, azomethine, quinacridone, dioxazine, isoindoline,
isoindolinone, perylene, phthalocyanine, pyrrolopyrrole and
thioindigo colorants and bismuth vanadate.
EXAMPLES
TEST METHODS
[0077] The isothermal crystallization time was measured using
differential calorimetry. The measurement of the film index takes
place by an optical evaluation system. Here, granules are extruded
into a film and defects in the film are characterized according to
their size. The film index is a value calculated from the number
and size of the defects, on which the defects have a weighted
influence according to their size.
[0078] Implementation and results of the laser transmission
measurements
[0079] The sample sheets of the IR laser-absorbing and the IR
laser-transparent material were both tested using a transmission
measuring arrangement consisting of a spectrophotometer and a
photometer sphere, which detects both directly transmitted light
and scattered light. For IR laser-transparent material with layer
thicknesses of between 1 and 3 mm, a transmission level of
typically 20-70% is displayed.
Materials Used
[0080] Durethan.RTM. B40 FA, commercially available polyamide from
Bayer AG, since 2004 from Lanxess Deutschland GmbH.
[0081] Durethan.RTM. B40 F, commercially available polyamide 6 from
Bayer AG, since 2004 from Lanxess Deutschland GmbH.
[0082] Durethan.RTM. B 38 FKA, commercially available polyamide 6
from Bayer AG, since 2004 from Lanxess Deutschland GmbH.
[0083] Durethan.RTM. B 30 F, commercially available polyamide 6
from Bayer AG, since 2004 from Lanxess Deutschland GmbH.
[0084] Radipol.RTM. A45, commercially available polyamide 66 from
Radici, Italy.
[0085] Durethan.RTM. T40, commercially available polyamide from
Lanxess Deutschland GmbH.
[0086] PEG 400 (Polyethyleneglycol 400) [25322-68-3-], commercially
available product from Aldrich.
[0087] Luviskol K25 (Polyvinylpyrrolidone K25) [9003-39-8],
commercially available product from Aldrich.
[0088] Luviskol K30 (Polyvinylpyrrolidone K30) [9003-39-8],
commercially available product from Aldrich.
[0089] Mistron Vapor RP6, commercially available talcum from
Luzenac.
[0090] Copper(I) iodide, CAS registry number [7681-65-4].
[0091] Potassium Bromide, CAS registry number [7758-02-3].
[0092] Luviskol K90 (Polyvinylpyrrolidone K90), commercially
available product from BASF AG.
[0093] Glass fibers CS 7928, commercially available chopped strands
from Bayer AG, since 2004 from Lanxess Deutschland GmbH.
[0094] All % and ppm data are by weight, based on the overall
composition.
Example 1
[0095] A solution of 468 ppm PEG and 33 ppm Luviskol K90 is added
to 6 kg of a commercially available polyamide (Durethan.RTM. B40F)
in a spiral mixer at 80.degree. C. and mixed for 2 h at 80.degree.
C.
[0096] In an extruder with a flat film die under a melt pressure of
36 bar, at a melt temperature of 257.degree. C. and a screw speed
of 30 rpm, the material is extruded into a film with a width of
approx. 300 mm and a thickness of approx. 50 .mu.m. The chill roll
temperature is 90.degree. C.
Example 2
[0097] A solution of 935 ppm PEG 400 and 123 ppm Luviskol K90 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0098] The extrusion conditions selected are as in Example 1.
Example 3
[0099] A solution of 877 ppm PEG 400, 150 ppm talcum and 65 ppm
Luviskol K90 is added to 6 kg of a commercially available polyamide
(Durethan.RTM. B40F) in a spiral mixer at 80.degree. C. and mixed
for 2 h at80.degree.0C.
[0100] The extrusion conditions selected are as in Example 1.
Example 4
[0101] A solution of 826 ppm PEG 400 and 173 ppm Luviskol K90 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0102] The extrusion conditions selected are as in Example 1.
Example 5
[0103] A solution of 244 ppm PEG 400 and 122 ppm Luviskol K30 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0104] The extrusion conditions selected are as in Example 1.
Example 6
[0105] A solution of 205 ppm PEG 400 and 123 ppm Luviskol K25 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0106] The extrusion conditions selected are as in Example 1.
Example 7
[0107] A solution of 667 ppm PEG 400 and 333 ppm Luviskol K30 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0108] The extrusion conditions selected are as in Example 1.
Example 8
[0109] A solution of 625 ppm PEG 400 and 375 ppm Luviskol K25 is
added to 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) in a spiral mixer at 80.degree. C. and mixed for 2 h at
80.degree. C.
[0110] The extrusion conditions selected are as in Example 1.
Example 9
[0111] Unreinforced PA 6 (Durethan B30F, a commercial product from
Bayer AG) was processed with the additives stated in Table 3 (with
addition of Luviskol K90) and glass fibers by compounding in a twin
screw extruder (ZSK 32 from Werner und Pfleiderer) at a melt
temperature of approx. 270.degree. C. to form a thermoplastic
molding composition. The melt was then spun off through a water
bath and granulated. The granules obtained were processed into
rectangular test specimens (125 mm.times.12.5 mm.times.1.5 mm) on
an injection-molding machine of the Arburg 320-210-500 type under
conditions conventional for molding compositions (melt temperatures
of 280.degree. C., mold temperatures 80.degree. C.) for laser
transmission measurements.
Examples 10-14
[0112] Unreinforced PA 6 (Durethan.RTM. B30F, a commercial product
from Bayer AG) was processed with the additives stated in Table 3
(with addition of Luviskol K90) and glass fibers by compounding in
a twin screw extruder (ZSK 32 from Werner und Pfleiderer) at a melt
temperature of approx. 270.degree. C. to form a thermoplastic
molding composition. The melt was then spun off through a water
bath and granulated. The granules obtained were processed into
rectangular test specimens (125 mm.times.12.5 mm.times.1.5 mm) on
an injection-molding machine of the Arburg 320-210-500 type under
conditions conventional for molding compositions (melt temperatures
of 280.degree. C., mold temperatures 80.degree. C.) for laser
transmission measurements.
Examples 15-17
[0113] Unreinforced PA 66 (Radipol.RTM. A45) was processed with the
additives stated in Table 5 (with addition of Luviskol K90) and
glass fibers by compounding in a twin screw extruder (ZSK 32 from
Werner und Pfleiderer) at a melt temperature of approx. 290.degree.
C. to form a thermoplastic molding composition. The melt was then
spun off through a water bath and granulated. The granules obtained
were processed into color plaques (40 mm.times.60 mm.times.2.0 mm)
on an injection-molding machine of the Arburg 320-210-500 type
under conditions conventional for molding compositions (melt
temperatures of 300.degree. C., mold temperatures 80.degree. C.)
for laser transmission measurements.
Comparative Example 1
[0114] 6 kg of a commercially available polyamide (Durethan.RTM.
B40 F) are subjected to heat stress as in Example 1 and processed
as in Example 1.
Comparative Example 2
[0115] 6 kg of a commercially available polyamide (Durethan.RTM.
B40 FA) are subjected to heat stress as in Example 1 and processed
as in Example 1.
Comparative Example 3
[0116] 6 kg of a commercially available polyamide (Durethan.RTM.
B40 FKA) are subjected to heat stress as in Example 1 and processed
as in Example 1.
Comparative Example 4
[0117] 173 ppm of Luviskol K90 are added to 6 kg of a commercially
available polyamide (Durethan.RTM. B40F) in a spiral mixer at
approx. 140.degree. C. and mixed for 2 h at 140.degree. C.
Comparative Example 5
[0118] 6 kg of a commercially available polyamide (Durethan.RTM.
B40F) are subjected to heat stress in a spiral mixer as in
Comparative Example 4.
Comparative Example 6
[0119] Unreinforced PA 6 (Durethan B30F, a commercial product from
Bayer AG) was processed with the additives stated in Table 3
(without the addition of Luviskol) and glass fibers by compounding
in a twin screw extruder (ZSK 32 from Werner und Pfleiderer) at a
melt temperature of approx. 270.degree. C. to form a thermoplastic
molding composition. The melt was then spun off through a water
bath and granulated. The granules obtained were processed into test
pieces (rectangular test specimens, 125 mm.times.12.5 mm.times.1.5
mm) on an injection-molding machine of the Arburg 320-210-500 type
under conditions conventional for molding compositions (melt
temperatures of 280.degree. C., mold temperatures 80.degree. C.)
for laser transmission measurements.
[0120] The products from Comparative Examples 1, 2 and 3 as well as
Examples 1 to 8 were investigated with respect to their isothermal
crystallization times. The data are compiled in the following
tables.
Comparative Example 7
[0121] Unreinforced PA 66 (Radipol.RTM. A45) was processed with the
additives stated in Table 5 (without the addition of Luviskol) and
glass fibers by compounding in a twin screw extruder (ZSK 32 from
Werner und Pfleiderer) at a melt temperature of approx. 290.degree.
C. to form a thermoplastic molding composition. The melt was then
spun off through a water bath and granulated. The granules obtained
were processed into color plaques (40 mm.times.60 mm.times.2.0 mm)
on an injection-molding machine of the Arburg 320-210-500 type
under conditions conventional for molding compositions (melt
temperatures of 300.degree. C., mold temperatures 80.degree. C.)
for laser transmission measurements. TABLE-US-00001 TABLE 1
Isothermal crystallization times at 200.degree. C. Isothermal
Polyvinyl- crystal- PEG 400 Polyvinyl- pyrrolidone lization time
content pyrrolidone content at 200.degree. C. Test [ppm] type [ppm]
[min] Comparative 0 -- 0 4.7 Example 1 Comparative 0 -- 0 4.0
Example 2 Comparative 0 -- 0 3.0 Example 3* Comparative 0 K90 0 4.2
Example 4 Example 1 468 K90 33 5.2 Example 2 935 K90 65 5.9 Example
3* 877 K90 123 3.7 Example 4 826 K90 173 6.7 Example 5 244 K30 122
5.8 Example 6 205 K25 123 5.7 Example 7 665 K30 333 5.8 Example 8
625 K25 375 5.5 *contain 150 ppm talcum
[0122] The laser transmission values of the compositions according
to Comparative Example 6 and Examples 9-12 were determined in the
freshly molded state and after tempering (post-crystallization 4
h/120.degree. C.). The data are compiled in the following tables.
TABLE-US-00002 TABLE 2 Comparison of film indices Polyvinyl- PEG
400 Polyvinyl- pyrrolidone content pyrrolidone content Film Test
[ppm] type [ppm] index Comparative 0 K90 174 9968 Example 4
Comparative 0 -- 0 338 Example 5 Example 4 826 K90 174 84
[0123] TABLE-US-00003 TABLE 3 Composition of the molding
compositions for processing by injection molding/laser transmission
welding Cp. Ex. Ex. Ex. Ex. Ex. Ex. 9 10 11 12 13 6 PA6,
additives.sup.1) [%] 69.948 69.3 68.8 68.7 67.8 70 Glass fibers [%]
30 30 30 30 30 30 Bayer CS 7928 Luviskol K90 [%] 0.052.sup.2) 0.7
1.2 1.7 2.2 .sup.1)Additives in conventional amounts and believed
to have no criticality in the context of the invention included
nucleating agent (175 ppm microtalcum), mold release agent (0.16%
montan ester wax, ethylene glycol bismontanoate) .sup.2)Metered as
a 17.36% solution in PEG 400
[0124] TABLE-US-00004 TABLE 4 Results of the transmission
measurements* on 1.5 mm thick test pieces Test Wave- specimen Pre-
Cp. length thickness treatment Ex. Ex. Ex. Ex. Ex. Ex. [nm] [mm] of
samples 9 10 11 12 13 6 810 1.5 None, 59 60 61 61 62 56 freshly
molded 1065 1.5 None, 64 66 66 67 68 62 freshly molded 810 1.5
Tempered 54 56 56 56 57 53 4 h 120.degree. C. 1065 1.5 Tempered 60
62 62 63 64 59 4 h 120.degree. C. *Total transmission [%],
measuring instrument PE Lambda 900, 0.degree./diffuse, ref. air T =
100%
[0125] Since all the samples are made of very strongly scattering
material, the total transmission was evaluated as the sum of direct
and diffuse transmission.
[0126] The samples corresponding to the comparative examples have
much lower transmission at 1000 nm and in the adjacent wavelength
range, while the samples according to the invention of Examples 1-4
with Luviskol additive display significantly higher transmission.
TABLE-US-00005 TABLE 5 Composition of the molding compositions for
processing by injection molding/laser transmission welding Ex. 14
Ex. 15 Ex. 16 Cp. Ex. 7 PA66, additives.sup.3) [%] 54.7 54.2 53.7
55.9 T40 [%] 9.1 9.1 9.1 9.1 Glass fibers [%] 35 35 35 35 Bayer CS
7928 Luviskol K90 [%] 1.2 1.7 2.2 .sup.1)Additives in conventional
amounts and believed to have no criticality in the context of the
invention included nucleating agent (175 ppm microtalcum), mold
release agent (0.16% montan ester wax, ethylene glycol
bismontanoate) .sup.2)Metered as a 17.36% solution in PEG 400
.sup.3)Additives in conventional amounts and believed to have no
criticality in the context of the invention included heat
stabilizing agent (350 ppm copper(I) iodide, 990 ppm potassium
bromide)
[0127] The laser transmission values of the compositions according
to Comparative Example 7 and Examples 14-16 were determined in the
freshly molded state and after tempering (post-crystallization 4
h/120.degree. C.). The data are compiled in table 5. TABLE-US-00006
TABLE 6 Results of the transmission measurements** on 2.0 mm thick
test pieces Sample Test character- Wave- specimen isation Cp.
length thickness Pretreatment Ex. Ex. Ex. Ex. [nm] [mm] of samples
14 15 16 7 950 2.0 None, 600 651 705 543 freshly molded 950 2.0
Tempered 4 199 209 217 194 h 120.degree. C. **Total transmission
[%], measuring instrument Prolas Laser Spec (calibrated with
colored filters made of glass)
[0128] Since all the samples are made of very strongly scattering
material, the total transmission was evaluated as the sum of direct
and diffuse transmission.
[0129] The samples corresponding to the comparative example have
much lower transmission at 950 nm and, while the samples according
to the invention of Examples 14-16 with Luviskol additive display
significantly higher transmission.
[0130] Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *